Mike Brown's Planets: family

Showing posts with label family. Show all posts

The end of the fall

The fall term always gets a little overwhelming, as classes get into session and lectures need to be written, problem sets graded, exams created. I have an amazingly long backlog of things about which I want to write at this point but which I have not yet had the time to even get started. To top things off, my life appears to be changing forever. Most of these pieces get written on weekend afternoons while Lilah is napping. But the days of napping appear to be coming to a close.I understand intellectually that this is likely, after all, few 10 year olds nap, but I had never really stopped to think about the effect on my life. It’s not all bad; being able to pondering going out to do something with Lilah in the afternoon could be quite fun! But it will definitely gobble up my quiet afternoon writing time. But, today, after a late Halloween night and a no-doubt sugar-induced-early-morning wakeup, Lilah is currently snoozing away and I am going to now type as quickly as possible. Ready? Go! (Halloween? Yes, I started writing this almost a month ago, giving a perfect demonstration of the point I am trying to make.)

Back at the end of August I asked everyone to review my paper on Titan fog, and, to my surprise, many people took the task extremely seriously. The paper was discussed in classes and in on-line forums and was stared at by many eyes. If you recall back in August one of the reasons for attempting this open review was the fear that having only a single official reviewer leads to a huge random factor as to whether or not you will get anything useful out of the process. In this case, I have to say that the official review was pretty difficult to decipher. The reviewer commented on a few typos, complained about the location of the references, and said that the paper was generally incomprehensible.

Incomprehensible? Now, I will admit to having written papers that are incomprehensible before (how about this one; I can barely understand it myself 20 years later), but I actually thought that the paper was pretty clear. What’s more, of the many comments I had gotten from outside the official review process, no one had quite said “incomprehensible.” So what was going on here?

I reread the paper several dozens of times, and reread all of the comments that I had gotten, and realized, I think, the source of the problem. I think I was much too terse in my explanation of what I had actually done. Sure, I discussed fog and its discovery in gory detail. But I perhaps did not do a great job of describing how I really sorted through all of the data to find fog. It’s a pretty crucial step. If you don’t provide enough details in your paper that someone else could come after you and reproduce precisely what you did, you have failed an important point of having a paper in the first place.

One reason for describing all of this poorly was that the real process was actually quite different from the way I attempted to describe it in the paper. The real process consisted of this: I was looking at a bunch of pictures of Titan and said “Whoa; what the heck is that?” That turned out to be fog. I suspect that many discoveries are made that way, but if you read scientific papers you will rarely learn that fact. If you read my paper, you will find something like “Fog is very important so one fine day we decided to go look for fog on Titan. And we found it.”

OK, partially this description is true. After the first few times of accidentally seeing the fog we did, one fine day, systematically search through the entire data set. But that description was all pretty muddled.

The solution was a nearly complete rewrite of the paper. Had I just gotten the official review I would have fixed the typos and reworded a few things here and there and wondered what the heck the reviewer was talking about, but with the strength of the large number of comments, I could really tell what people were seeing and reading and I could make it significantly better. At least I think it is. But don’t take my word for it. Remind yourself of the first version, here. And now go read the new version here as it is about to appears in this week's Astrophysical Journal Letters. You still will not read the new version and realize that the real way we found fog is that we stumbled on it accidentally, but you will at least, I think, have a better idea of precisely what we did and how we did it. Want to go find fog yourself? I think the roadmap is now significantly more clear.

My conclusion from this experiment? I can’t tell you whether this system will always lead to such dramatic improvements in the quality of a paper, but in this particular case there is no doubt that when you read the two versions of the paper and you note any improvements almost all of those improvements came from the open review, rather than the official review. All of the comments that were sent to me were incorporated in one way or another. And for that, I would like to say a hardy THANK YOU to everyone.

But wait, there’s more!

Fresh on the heels of the Titan fog paper, I have submitted a paper to the Astronomical Journal called “The size, density, and formation of the Orcus-Vanth system in the Kuiper belt.”

This paper, I will admit, is less accessible than the paper about fog on Titan, yet, still, would you give it a read? It’s been posted online for a week and one reader already pointed out a rather stupid math error (thanks Alan Martin) of the sort that creeps into papers when you work on them one hour a week for 3 months (the error is still there, until we fix it in the next round of reviews, so feel free to go track it down and marvel at how stupid I sometimes can be).

Normally I would spend a few pages here telling you what the paper is about but, conveniently, I did that last spring, when we were searching for an appropriate name for the moon of Orcus. Go back and reread the post about coming up with names for the moon of Orcus, where I talk about the strange characteristics of what we now call Vanth. And, with a bit of continued Lilah napping over the weeks to come, stay tuned for thoughts about searching for the real Planet X, why I hate the 5 dwarf planets, and strategies for Lilah-weekend-nap-inducement.

And look! Lilah is done with her nap, and ready to start in on last night’s candy. Back to the sugar frenzy. (and with that, Lilah was awake, and we were off, and now it is a month later and Lilah is settled into a post-Thanksgiving nap and I finally have a spare moment to finish and post. Classes end next week for the year, so I look forward to a bit more time for reflection soon. Stay tuned.)

Planetary Placemats

This morning Lilah started asking about Christmas. With her fourth birthday now more than a month behind her it seems to the natural thing to start contemplating. As a warm up, she started trying to remember presents from last Christmas.

“Daddy! Daddy! You gave me those baby scissors!” she exclaimed, running over to her little table sitting in the middle of the kitchen and pulling out a pair of 4-inch miniature yet quite sharp scissors. She uses these most every day, though we almost lost those on a plane ride to Seattle this summer when we unthinking brought them in carry-on. I was both relieved and flabbergasted when the security inspector pulled them out, looked at them, and decided that they were OK to bring aboard.

“But Daddy, where is my mat?”

Mat? Mat? What mat? I thought and thought until I remember, with a little shock, that for my own amusement, I got Lilah a plastic “Nine Planets Placement” for Christmas last year that had nice photos and facts of all nine (ahem) planets. It had gotten shoved under a pile of other placemats in a drawer, but I dug down, pulled it out, and Lilah cheered.

“The planets!” Lilah exclaimed.

“Ugh” I thought.

With the third-year anniversary of the demotion of Pluto having just occurred, I’ve been thinking a lot about planets again (or perhaps I should just say “still”). But rather than worrying about planet classification anymore, which I think is on pretty solid ground these days, I’ve been wondering about the people who simply can’t give up on the concept that Pluto simply has to be a planet. Why are they so attached to the 18^th largest object in the solar system when they probably can’t even name all of the 17 larger things? (try this at home: can you without looking it up?)

Lilah’s placemat drove home a likely part of the problem. Most people have absolutely no idea what the solar system actually looks like. They see pictures of planets of placemats, on lunch boxes, on walls at school, but none get the scale of the solar system even remotely correct. Why? First: it’s boring. The solar system is mostly empty space. How much empty space? If you were to draw a top-down view of the solar system from the center out to the edge of the Kuiper belt, it would be 99.999999% (that’s 8 nines, if you’re counting) empty. And 99% of that non-empty fraction is taken by the sun. Making a placemat with that much empty space is pretty dull (though presumably you would save on printing costs). I would show you here what it would look like, except that you would need to view it on a monitor with 12,000 pixels across (about 10 times your typical laptop screen). The sun would occupy only one pixel in the center. You’d see nothing else. If you had grown up with a picture of the real solar system on your placemat, you would be forgiven for thinking the number of planets was precisely zero.

We need a better placemat. What’s the solution? There is no choice except to dispense with trying to depict both the distances between planets and the sizes of planets on the same scale. You can do a little better if you shove the sun almost out of the frame, keep the relative distances between the planets correct, and exaggerate the sizes of planets by a factor of about 8000.

(The Kuiper belt with Eris and Pluto and the rest is really there, way off on the right side. Try squinting.)

This solution still does not make for a great placemat. It’s still mostly empty space, and most things are too small to see well. If Jupiter is going to fit on your placemat at all (and let’s not even talk about the sun), Mercury is going to be so small that it will look like just a tiny dot (and, again, let’s not even talk about Pluto, which is half again smaller). If you had grown up with this placemat you would probably have a lot of respect for Jupiter and Saturn and wonder why everyone made such a big deal about the rest of them.

As a placemat maker, there is one other step you can take while still maintaining scientifically integrity. You can keep the planets in the right order, but give up on showing their true distances from each other. Shoving the planets together a bit more allows them all to be somewhat bigger. Now you can even make out Ceres, the largest asteroid. The band of tiny Kuiper belt objects begins to be visible.

“Alas!” cries the honorable maker of placemats. “How am I to put any artwork on tiny disks that size? What of the canyons on Mars? The scarps of Mercury? The mottled face of Pluto?”

There is a solution, of course. Forgo almost everything. You’ve already had to throw away the correct relative spacings between planets to make the placemat more interesting. Now also throw away the correct relative sizes! Make Jupiter and Saturn significantly smaller, make the tiny tiny terrestrial planets significantly bigger. Grossly exaggerate the size of puny Pluto. This is the perfect solution. This is Lilah’s placemat.

I find this solution perfectly awful.

My objection here is not the inclusion of Pluto as a planet (that’s just anachronistically cute, sort of like ‘here be dragons’ on an old map), my objection is that everything about the solar system is so wrong that of course people are going to be generally confused. How could astronomers possibly vote to get rid of Pluto when there it is, as big as Mercury, nearly as big as the earth itself?

Just how bad is it? If you take Jupiter to be the right size and scale everything from there, Mercury, Venus, Earth, and Mars should be 6,4,4, and 5 times smaller, respectively. The smallest ones, Mercury and Mars, are the most exaggerated.

The giant planets are a bit odd. Saturn is actually 80% too small, presumably because its rings take up too much space to be aesthetically pleasing. Uranus and Neptune are 1.2 and 1.5 times too big, respectively.

And Pluto? It remains the runt even in this solar system, where its size is exaggerated by a factor of 10.

If you grew up with a placemat like this, or a wall poster in your third grade classroom, or a lunch box you carried every day, I now understand why you feel Pluto still deserves to be a planet. It’s because you and I are talking about entirely different solar systems. Even I would agree to Pluto’s special place in the solar system of Lilah’s placemat. Sadly, that solar system and the real solar system have little in common.

I do have a better solution for the placemat makers out there. It keeps the relative sizes of planets correct and keeps their ordering correct, but, like all of the ones above, it has to dispense with the relative spacing between planets. The trick, though, is to pile the planets on top of each other, and to not even show all of the monster Jupiter. You can pack much more into the frame, like this.

There is room on this placemat to put real depictions of the planets. And you can even see many of the dwarf planets out in the Kuiper belt. If you look carefully, you can see the elliptical Haumea and you might even be able to identify a few other of your favorites.

Imagine a world in which this was the image that children – that adults! – had of the solar system. Would we even be having conversations about Pluto’s planethood? It seems pretty unlikely to me. Rather, we would talk of the great difference between giant planets and terrestrial planets, we would talk of the band of asteroids, and we would talk of the ever-increasing number of tiny icy objects out there on the very edge of the solar system. In short, we would talk science rather than definitions. But, occasionally, we would remember the old solar system of our youth and talk nostalgically to our children, and say “when I was your age, Pluto was still a planet” and then, when our child looked up quizzically, we would look down in the corner of the placemat, and try to point out the former planet amongst those many many objects and realize that we had absolutely no idea which tiny point it even was.

Thank you from the future

Being a professor at Caltech, I get to dress up in a gown and funny hood one morning every June and sit on stage, watch hundreds of new Doctors and Masters and Bachelors go by and listen to a commencement speaker impart words of wisdom on the graduates. One June, a few years ago, I even got to be one of those commencement speakers. I spoke at the graduation ceremony for Cal State LA in their football stadium, with 20,000 people in the audience – a personal record that I suspect will never be exceeded – and my image projected, rock star style, on multiple giant screens around the stadium. I had a few butterflies in my stomach that morning. But I managed to give a speech that I ended up liking. It went something like this:

First, I’d like to thank President Rosser for inviting me to be here to share this morning with you. I’d like to thank all of the students for inviting me, too, except that I can see all of you down there discretely picking up your programs and flipping through saying “um, who exactly is this guy again and why is he here?” So let me help you out with those two because really if you ask your neighbor he or she probably won’t know either, but that’s OK.

Who am I? You got the quick intro: astronomer, professor at that much smaller university about 5 miles north of here, discoverer of the 10^th planet or perhaps destroyer of the 9^th planet depending on who you talk to. And I guess those are the official qualifications for why I’m here talking to you today. But let me tell you how I would actually introduce myself if we met out in the parking lot. I’d probably ask where you were from and I’d say “oh I’m your neighbor; my house is about 10 miles up the road that way.” And then I would probably tell you that I teach geology classes to large groups of Caltech freshmen many of whom seem to have never been outside during the daytime before I take them and make them look at the world around them. And then I would start talking about my wife and our 11 month old daughter and you’d have to find a way to get me to shut up because, you know, you need to be somewhere by dinner time and I might keep talking for weeks.

OK. So that’s who I am. The next question is: why am I here? The goal of a commencement speech is to give you a seed of advice at this precise turning point in your life – some seed that is going to implant in you and grow and help steer you as you commence on your new life. It’s a powerful idea that that I could do that, that I could transfer a little bit of wisdom from me to you to help steer through all of the cross currents and distractions of real life to finally get to your ultimate goal. Now that would be seriously influential.

But I’ve got bad news for you, though. I’ve got no advice to tell you how to get along in life. No little words of wisdom. No seeds to plant. As my wife will attest, I barely know how to get along in life myself, and if I had any seeds I probably set them down somewhere in the other room and now I can’t remember where I put them even though I just had them a second ago. I can’t really give you any advice on how to get to the future because the most important thing that you will realize – which you probably already realize since you have made it this far -- is that really you just have to figure it all out on your own. OK maybe that even counted as advice, but if that’s all you get after all of those years of classes and driving and rearranging schedules to get here on time then you should really ask for your money back. No, really, I’ve got no advice to give, unless, of course, you wanna run off and find planets, then I’m definitely your guy. But otherwise? Nothing really.

So I thought: what can I do? No advice to give, but I’m supposed to talk for ten minutes I can just try to be funny for a few more minutes then we can get on with the serious business of whooping and hollering as all 3600 of you walk across the stage. Then I remembered what my wife told me: scientists are not funny people. Why do you think they put them all in the far back of the stadium there? Not funny at all. Don’t even try.

So I’m going to go out on a limb and try to do something that is a lot harder than trying to be funny, which is trying to be serious. I do have something I want to tell you, which is maybe better – or at least more rare – than advice. I want to tell you thank you. Thank you for everything that you’ve done to be sitting right there right now. But really this is not from me, I really want to tell you thank you from the future. And you might think that I am uniquely qualified to talk about the future since I’m an astronomer and all, but, um, really, being an astronomer has very little to do with predicting the future. That’s an ASTROLOGER. They’re the ones that get paid better. But people do get confused all the time.

So it’s not that I am an astronomer and thus know the future, no, I think that the one qualification maybe I have for talking about the future really is my 11 month old daughter. Some of you down here – and certainly many of you out there – know what having a child does to you: you immediately start projecting to the world of the distant future, but you also start thinking a lot about the past and your own parents.

So before I start talking to much about the past, first let me ask: How many of you are in the first generation of your family to go to college? (At Cal State LA first generation college students make up the majority of the population.) This thanks goes to you, but the rest of you need to listen to because it will be your job to pass this thanks on to the right person in your own family.

So first, let me admit: I’m not one of you. I’m in the second generation to go to college.

My father grew up in a small Missouri cotton farming town along the Mississippi River. My mother grew up in a small Illinois manufacturing town along the Mississippi River Neither of their parents had gone to high school in their little river towns. My mother’s family came from recent German immigrants and ran a series of grocery stores in town. My father’s family came from all over – Ireland, France, Nebraska, Pennsylvania – before settling down along the river and opening a small business repairing the newly invented TV sets. By the end of the 1950s with college opportunities beginning to expand around the country they both set off to do something no one in their family had never done: go to college. My mother traveled down the river to the big town of St. Louis; my father went up the river to the big town of St. Louis; and they both arrived at St. Louis University with little idea of what was in store for the next 4 (or 40) years

My mother and father both went to college in the 60s and so in my family there really wasn’t much question of college vs. no college. It was simply a where (in Alabama the choice was usually based on whether you were a fan of the University of Alabama or the Auburn University football team). But things were different for my parents. My father grew up in a small cotton farming town along the Mississippi. My mother grew up in a manufacturing town further north along the Mississippi populated by German immigrants.

And, so, in case you haven’t figured this part out yet, my parents are you.

And if my parents are you, I am your children.

You are my parents. I am your children. Your children, though, will never quite understand this well enough to thank you for all that you did. So I’m going to thank you instead.

I’ve got a second thank you that I need to say this morning. It’s not really for you, so I’m only going to give it to you so that you can pass it on. And this is the thanks for the parents and the siblings and aunts and uncles and grandparents and cousins and everyone else who is here supporting you today and who has been supporting you through all of this. Those people – all of you out there – are like my grandparents pushing their children from opposite ends of the Mississippi River in the same direction towards their own goals. The funeral for my grandmother – the last of my living grandparents – was just this last Monday in that little Mississippi River town. Until I sat down to think about what I was going to say this morning to you it never really occurred to me to think very hard about all that she had gone through that allowed me to be where I am today. It certainly never occurred to me to tell her thanks. But she deserves the same thanks that I just extended to you. I wish this one could be from me to her, but I’ll have to settle for from the future to all of you. For your parents out there, your grandchildren – present and future – thank you for all of the things that you did that will make their lives better, even though they won’t really know most of them.

Once you start thanking people it actually gets kind of addictive. Particularly when you are actually doing the thanking for someone else in the future. I’ve thanked you from your children and from your grandchildren, but I’ve got one more that is a little closer to home for me. I think a lot about my daughter these days and I think a lot about the future that she is going to have. In maybe 21 years or so – let’s say June of 2027 -- she could be sitting down right there where you are now. What will the world be like then? I sometimes think the bad thoughts: with 20 more years of global warming will LA be a place that we can live? Will the WORLD be a place we can live? Will the top speed on the freeways be 10 MPH? Will some psychopath figure out how to get a nuclear device into LA before Jack Bauer can stop him? But you think the good thoughts, too: in 20 more years maybe people will have learned to be nicer and more understanding. For the most part, though, most of these things are going to be imposed on us all from the outside and there will be little we can do. [sorry; this is a commencement speech faux pas. I’m not supposed to admit to you that much of what happens in the world you can do little about. Ok, for the record everything is possible you can be anything you want to be and completely change the world and we all believe in you to do anything. OK? OK. Now back to the real world]. OK, no, but really most of the thoughts that I have when I think about what the world will be like in my daughter’s future involve things that few of us – no matter how influential Time magazine says we are – can do much about. They are just the fabric of life, the collective interactions of the millions of people living out their lives at the same time in our community. And I can’t tell the future, so as much as I try to use the Tarot cards they issue you with the astronomy degree to predict what is going to happen, I really have absolutely no clue whatsoever. But there is one thing that I know – one part of my daughter’s life and future – that will be a constant no matter which of these things – good or bad – comes about. That one part will be you. You are the future fabric of this community of Los Angeles. You know, somewhere out there might be my daughter’s mayor – and by now you gotta trust that I don’t mean that in the cheesy commencement speech “you can be anything” kind of way – I mean that in the very literal “somewhere out there might be my daughter’s mayor or maybe city council member or Senator or whatever” way. Really. It actually seems pretty likely doesn’t it? Somewhere out there might be the high school English teacher that inspires my daughter to go write the great American novel. Somewhere out there might be her older next door neighbor who feeds her cats when she is out of town. Somewhere out there might be the parents of her husband. [If so we will need to talk right after this ceremony is over]. Somewhere might be the owner of the first company she ever works for. Somewhere might be the doctor who delivers my own daughter’s own daughter. Big parts of the fabric of her life, of the fabric of this city are sitting right here.

So, as her father, I’d like to thank you. It will never occur to her to thank you for anything since you’re the fabric and people tend to take fabric for granted, but I’ll thank you from the future for making and being the city and community of her future.

And, OK, I have one request. Really just one thing for you to remember to do when you leave here today. (And, of course, don’t forget what I said before about thanking those people who are here for you today). I still really don’t have meaningful advice, but I do have this one request. You guys are the Los Angeles of my daughter’s future, the fabric of her life in this community. And I just ask that you be nice to her. And to look out for her. It’s not too much to ask of you is it? Just to be nice to someone? Like she’s your own daughter, or your baby sister, or your favorite niece? And I meant to bring with me a big poster board picture of what she looks like so you could know who you were promising to look out for and be nice to, but I got up way too early this morning – astronomers aren’t traditionally morning people – so I just plain forgot. No baby pictures for you, so you really don’t have any way of knowing what she looks like – although you probably wouldn’t go wrong by looking for someone who looks an awful lot like me but is a good bit shorter and much much much cuter– but still, you’ll never know for sure which one of the toddlers then kids then teens then adults that she is, so really I guess the only safe way to honor my request to be nice to my daughter is just to be nice to everyone. And look out for them. You are the future of everyone’s community of Los Angeles and I want you to look out for everyone. It will make the Los Angeles of all of our futures a better place to be.

Homeward bound

I’m on my way home today from a quick trip a third of the way around the world to use a telescope.

Astronomers are, of necessity, vagabonds. Sometimes the thing that you want to look at in the sky is only viewable from the southern hemisphere, so down to Chile you go. Sometimes the thing is so faint that only the biggest telescopes around are worthwhile, so it’s off to Hawaii. What’s rare, though, is to spend 24 hours flying from Los Angeles all the way to the Canary Islands – a group of high volcanic crags off the coast of Africa with a latitude almost identical to that of southern California – to use a telescope smaller than the one that is just a three hour drive from my house.

When, after a day of travel, I got to La Palma, the island whose highest peak is strewn with telescopes, and I stepped outside into the dark dark night sky, I was greeted with exactly the same sky that I see in Los Angeles. OK, there were many many more stars, but they were all in their right places, and nothing was there that I couldn’t have seen from home.

So why spend all of that time to travel to a telescope smaller than my local one when all of the same sights were visible? Because when it was night time in the Canary Islands the sun was still high overhead in southern California. And the thing I was hoping to see only happened right then. If I had stayed home and waited eight hours to look later I would have seen nothing.

Here is what I hoped to see: that night the funny oblong fast spinning dwarf planet Haumea was passing directly in front of one of its satellites (Namaka is its name). If I could determine precisely when it happened and how long it lasted I could learn many things about Haumea (its size and crazy shape, maybe also its interior structure) and also about Namaka (how big it is, how much it is being tugged around by the other satellite, Hi’iaka). But all of this was happening so far away that the only way I could tell when Namaka disappeared behind Haumea was that the total amount of light coming from Haumea should dip by about 1%, So at the telescope I spent two entire nights doing nothing but staring at Haumea and measuring precisely how bright it was every two minutes. For comparison, I also checked a couple of stars nearby at the same time. If they stayed steady while Haumea dipped in brightness I would know I was in business.

It all sounds so simple.

In reality, though, stars never stay the same all night long. They get brighter as they get higher in the sky and fainter as they drop. Even on the clearest nights they fluctuate due to changing atmospheric conditions. Seeing this tiny drop in brightness of Haumea in the face of all of this intrinsic variability is a tough task.

But I tried.

After two nights at the telescope I am leaving with my laptop filled with pictures of the sky and my hopes high. Did we see it? Did we detect this tiny dip which told us that Namaka disappeared? I think so. I have a plane ride from London to Los Angeles tomorrow to look at the data more closely and convince myself what might or might not be there. But I think so.

If we didn’t detect anything it’s bad news. Perhaps our predictions are off, or it’s just too small of a blip for us to ever really see. But if we did detect it then our work is really just begun. Turning that little blip in the sky into concrete information about Haumea and Namaka will take a lot longer than tomorrow’s plane ride. There will be many more such trips around the world to be in precisely the right place when it happens again. There will be detailed computer models of the exact time and depth and duration of the blips. There will be confusion and ambiguity. But that is all in the future. For now I have the simple pleasure of long uninterrupted plane ride where I can stare and poke at the data, catch up on some reading, and think about these dwarf planets. And at the end I get to pick up my daughter from school and she’ll ask “Daddy daddy daddy did you see any stars?” and I’ll tell her that I did, but that the stars here at home are always the very best ones in the sky.

Baby Pictures

Last night, for the second time this decade, I got to have dinner and give a talk on the floor of the dome of the famous 200-inch Hale telescope at Palomar Observatory. It’s rare for anyone to give a talk on the floor of the 200-inch telescope, because Palomar, like every other large telescope around the planet, is used night after night after night looking at everything from the nearest asteroids to the edge of the universe. Few or no pauses are allowed for frivolities such as dinners and talks (in this case we got in, had dinner, gave a talk, and vacated the floor just as the sun was setting). So it was a treat when I got invited to speak to an intimate gathering of supporters of Palomar and Caltech – the university where I work and the one which, not incidentally, owns and operates Palomar – on the floor of the dome. It was even more of a treat because I had been the speaker at the last one of these dinner 8 ½ years ago, and it was particularly interesting to reminisce about what had happened in the almost-decade since then.

When I gave that first talk, in September of 2000, I was a young assistant professor at Caltech who had embarked on what I think it is fair to say was an audacious project: I was going to go find the 10^th planet. I had spent the previous two years systematically scanning a wide swath of sky using the seemingly ancient technology of manually slapping giant glass photographic plates to the back of a wide-field telescope, exposing the photographic plates to the sky for half an hour at a time, developing the photographic plates in the darkroom downstairs, and then looking at repeat exposures of the same patch of the sky to see if – perhaps! – I could find something that had moved. It was exactly what Clyde Tombaugh had done 70 years earlier that had led to the discovery of Pluto, but, no, I had the advantage of a much larger telescope and the use of computers to help analyze the final photographic plates.

At the time of the talk 8 ½ years ago I was in the third year of the project, where I was going back with a larger telescope to try to confirm anything that I thought I had detected during the first two years with the photographic survey. I told my audience sitting under the 200-inch telescope about what I was doing and about what I hoped to find. I told them about photographic technology versus the new digital cameras now widely in use. I told them about why I thought that after this third year I was going to have made that discovery I was hoping for and the 10^th planet would be in our grasp. It was, I daresay, a talk full of exciting promise.

It’s a good thing I wasn’t asked to give a follow up talk right away.

By the following year it was clear that my three year survey had found a grand total of absolutely nothing.

I told that story last night at the 200-inch telescope and everyone chuckled. They chuckled, of course, only because they knew what came in the years that followed. What came next? We scraped the photographic plates, installed experimental digital cameras, roboticized the telescope, and kept scanning and scanning and scanning. With the benefit of the faster and more sensitive digital cameras we slowly surveyed the whole northern sky and blew the outer solar system open.

Last night I showed my baby pictures from the past decade. I showed Quaoar, the first large Kuiper belt object that we found, the one named for the creation force of the local Tongva Native American tribe, the harbinger of larger objects to come. I showed Orcus with its newly named moon Vanth, and talked about its odd mirror-image orbit to Pluto. I showed Sedna, far beyond the Kuiper belt, in an orbit that takes 12,000 years to go around the sun, named for the frigid Inuit goddess of the sea, a beacon pulling us even further in the distant solar system. I showed Haumea, with her two moons Hi’iiaka and Namaka, spinning her was across the sky, I showed lonely Makemake, bird god of the Rapa Nui, the runt of the litter that produced the Big Three of Makemake, Pluto, and Eris. And then, of course, I showed Eris her, in all of her discord and strife, with her tiny moon Dysnomia circling her.

I really do feel like each one of these is like a child to me. And, like children, whenever the rest of them are not in the room, I will secretly tell you that this one is my favorite. They’re all my favorites. I can tell you stories about their little quirks, their odd habits, and a funny thing that this one did the other day when it thought no one was watching (did you know that the night before Namaka went right behind Haumea playing a little hide-and-seek with us? Silly little moon.).

Something else was particularly interesting to me about my talk 8 ½ years ago at Palomar. Something happened that day that I am certain I will never forget. I was inside the telescope waiting for the group of Caltech supporters to arrive, and finally hearing the knock on the outside door, I opened the door, and, as my eyes adjusted to the blinding outside light, I was greeted by the director of the group of Caltech supporters. She had worked on the Caltech campus for years, but somehow our paths had never crossed. I had certainly never seen her before. How do I know for sure -- you might ask. Trust me -- is my answer. I would have remembered. She walked in the door, and I fumbled my words introducing myself. Her name was Diane Binney.

Diane Binney doesn’t work at Caltech anymore, but she came on the trip to Palomar last night anyway. It was her first time back to the mountain since that time 8 ½ years ago when I gave a talk up there. She came to see old friends and revisit old places. And, since she hadn’t seen many of the people in a long time, she brought baby pictures of her own. She has a 3 ½ year old daughter named Lilah. Lilah has Diane’s last name as a middle name, but she gets the last name from her father. Me. Lilah Binney Brown.

Look up!

My wife noticed, many years ago, that every time I walk outside at night, the first thing I do is to look up. For a while she assumed that it was because I had a telescope operating somewhere and I wanted to see the condition of the sky, the locations of the clouds. Then she realized that I would even do it when she knew that I wasn’t using any telescope anywhere. It’s just what I always did: walked outside, looked up. Finally, she asked me about it. My first reaction was: I do? But then, after awhile, I realized: I do. I am always curious about clouds and about clarity, but mostly I just want to make sure that everything is right with the universe, that all of the stars are in place, that the moon has moved to whichever new spot in the sky it should be that night, that any of the planets that might be up are where they are supposed to be.

Sometimes I get a bit of a jolt, even though I know it is coming. When I fly to Hawaii and go use the telescopes out there I look up at night and see, oddly, that Orion is almost straight overhead, instead of low in the south like it is supposed to be. At that point my eye always travels north to try to find Polaris, now dangerously close to the horizon. Then I take a glance as far to the southern horizon as possible and I see something unsettling: stars I don’t know. I might as well be in another universe.

For all of my traveling the globe to go to telescopes, I’ve only been south of the equator once, for my honeymoon. When I went outside and looked up there, it was an odd combination of familiar and bizarre. In the north, Orion was flying overhead, but upside down. The bright red Betelgeuse, which translates as armpit of the giant, should really be called kneecap of the giant from there. The moon was also much further north than I was prepared for and it, too, was upside down. It really did give me that feeling that I was standing on the opposite side of the world, that my head really was pointing in a different direction than when I was at home.

One of the reasons that I was surprised when my wife mentioned to me that I always look up is because I was a little surprised that everyone else doesn’t do the same thing. The grand vista of the stars and the planets is above us night after night, and all you have to do is to look up. Most people are shocked when you explain to them, for example, that you can look at Betelgeuse and you can look at Sirius, and you can see that they are different colors. They’re amazed to know that that bright light in the twilight sky is not an airplane but is indeed the planet Venus. They are truly floored when you suggest to them that they get out a pair of binoculars and look at Saturn – high over head in the sky these days and you can see the rings. Or the moons of Jupiter. All of the stuff is out there for the taking.

I was in New York City this past week to give a lecture at Sarah Lawrence College. To get to Sarah Lawrence I walked my way down to Grand Central Station in the late afternoon, stared at the board of departures trying to figure out which was the right train to take, bought my ticket at an automated dispenser, and then had a few extra minutes to kill before the train left, so I stepped back against a wall to watch the people go by. Everyone was in a hurry across the floor, trying to catch a train or make their way home. But somebody on the other side of the concourse was doing something that no one else was doing, so it caught my eye. She was looking up. Curious what might be attracting her attention, I did the same, and there, inside of the building, a hundred feet up on a huge dome ceiling, was the sky.

Not just any sky, a spectacular painted sky with stars in place but also the constellations drawn and the ecliptic and celestial equator drawn through! Orion (with a gleaming Betelgeuse in his armpit) battles Taurus the Bull in the heart of the flowing Milky Way while winged Pegasus watched high above. Castor and Pollux look, to me, like they are plotting mischief to the side.

And, with thousands of people streaming through the concourse, there was one – now two – people actually looking up to notice. It reminded me of, well, of Los Angeles at night, where no one bothers to look up.

Because the constellations were painted along with the stars, I concentrated on the constellations. They were what was new to me. When I look at the real sky, I look at the stars, and don’t think much of the constellations, since no one has taken the time to paint them in the sky. But here they were beautifully drawn with sparkling stars as highlights.

Something was a little funny, though. At first, since I was concentrating on those new drawings, instead of on the real stars, I didn’t quite get it. But then it hit me: Taurus is on the wrong side of Orion. Castor and Pollux are switched. And what is Pegasus doing high to the left instead of to the right? It was like the real sky, only backwards.

Backwards is not the same as upside down. Backwards is like a mirror. Backwards it like you never ever really see it anywhere on earth, or, really, anywhere else in the Universe.

My scientific, educational self was offended. What? They spend all of this effort to put the sky on the ceiling and they get it wrong?

The ceiling, though, was copied from artwork that was supposed to be illustrating what the sky looks like from outside the Celestial Sphere. Except for one thing: there is no such thing as a Celestial Sphere. The Celestial Sphere is what you would think was out there if you considered the whole night sky to be a planetarium with little points of light a small distance away. Imagine now that you can sit outside the planetarium and see the stars. This is what the ceiling at Grand Central looks like.

And then I went from slightly offended by the inaccuracy, to thoroughly charmed by the historical accuracy. Yeah, I thought. People really used to think that you could step outside and look in and this is what they would see. This ceiling is fantastic.

It is the International Year of Astronomy.

A few weeks ago I participated in a panel discussion with 4 other astronomers as part of the celebration of the Internation Year. The event was sponsored by, among others, Discover Magazine. In this month’s issue they have a [heavily edited] transcript of the discussion amongst the five of us from the event. I am proud to say that, in the [heavily edited] transcript, I got the last word from the night, based on a question from the audience. Discover Magazine gets the last word:

Audience: What are your hopes for this year’s International Year of Astronomy

Brown: If there is anything I can convince people to do, I want people to not just sit here and listen to astronomers and think about astronomy but to look at the sky. So what I want everyone to do where you walk out tonight is to look up. You’ll see Orion, you’ll see Sirius. Just look up at the sky for a minute and think about what’s out there. That’s what I want.

We'll always have Regulus

I find Paris disorienting.

First, I missed an entire nighttime. When my wife and I arrived at the airport to embark on our vacation it was a southern California late afternoon. When we landed – first in Zurich – it was a Swiss early afternoon. Somehow I had missed an entire fast-forward cycle of the sun setting, the stars rising, and the sun rising again, all in the space of about 4 hours. When I first closed my window shade and then closed my eyes on the airplane – somewhere over Salt Lake City, I think – I made a mental note to be sure to try to open up and see the sunrise – over Greenland, I guessed. But even for the fitful sleep of a bumpy airline seat the sunrise came too quickly. When the thought to open my eyes and look out the window finally solidified sufficiently inside my head we were already over Ireland. I slid the window shade open a tiny crack to take a peak and the entire darkened airplane cabin was blasted with late morning glare. My wife, still attempting to sleep in the seat next to me, added her own glare to that of the sun and I quickly closed the shade. By the time we landed in Zurich and then finally continued on to Paris the sun was already on its way down again, but, still, I feel like a lost nighttime in there somewhere. Nights are precious things, and one should not lose them lightly.

If losing a nighttime were not disorienting enough, I believe that the streets of Paris are uniquely designed to make me lose my sense of direction. I pride myself, most of the time, with having a finely tuned sense of direction. I tend to be able to get from point A to point B by dead reckoning, no matter how many twists and turns and detours are along the way. So on the streets of Paris my general navigational strategy is to take a look at a map to see where we are and where we would like to be, and then I head off in what seems to be the correct general direction knowing that I will get to where I’m going. But the streets of Paris are tough. It’s not just that they aren’t oriented along a north/south axis. It’s not even that they aren’t oriented along any single axis. And it is not even that the streets sometimes curve. It’s that all three of these occur in small quantities. A street that I am on starts out general north-northwest, which, in my head, I probably think of as “northish” and then the street slowly, imperceptible turns west or even perhaps a little south. I then take a left turn onto a street which I think of as going westish when, in fact, it is more like the north-northwest direction I was originally headed. Do that a few times and there is no telling which way you are really going.

The first night we arrived, jetlagged and awake at midnight, I thought it would be fun to walk down to the Seine to see Notre Dame lit up at night. Point A: our hotel. Point B: Isle de la Cite. Direction: north-nothwest. After about 45 minutes of walking in the bitter bitter cold (ok, I live in southern California, so the fact that it was only a few degrees above freezing qualifies as freezing for me) we stumbled out of some small twisty city streets directly into the Pantheon, which was indeed spectacular all lit up after midnight. I’d never been to the Pantheon before and didn’t quite know where we were. I finally got out the map. We were a block from our hotel. Point A to Point A in just 45 near-freezing minutes. My wife gave me a similar glare to the one from earlier that morning.

Paris is a city to which my wife and I have both been a few times, but which we do not know well. We’re staying in a part of town which I have never visited. Our college French is rusty. An after flying for 12 hours and missing a full sunset and sunrise and finding myself unable to make it to one of the most obvious landmarks in town and struggling to remember the French phrase for, say, “Excuse me, madame, but do you know why I seem to keep walking in circles?” I feel very very far away from home in Pasadena. Looking at the globe you can see just how far it is, as I kept explaining to Lilah, our 3 ½ year old, who wanted to understand exactly where we were going to be (a place she calls “Parisfrance”) while she stayed home with her grandparents. “Parisfrance is really really far away Daddy. If I were on the airplane I would have to fall asleep.” A wise girl, I think.

But then, still trying to straighten out my post-midnight rambling route, we hit a slight opening to the sky and the clouds clear a bit and there, a bit low in the sky in about the direction we’re heading is a bright star and a little backwards question mark of fainter stars. The constellation is unmistakably Leo. The star is Regulus.

“Let’s turn around” I say to my wife. “We’ll be going in exactly the right direction.”

It’s the same sky. Pasadenacalifornia or Parisfrance look out into the same night and lie underneath the same stars. Fly 12 hours, miss a sunset and sunrise, forget the language if you want, but Regulus will still be there. I used Regulus once to get myself unlost while driving in New Jersey trying to figure out the direction of the shore (my friend in the car with me couldn’t figure out why I pulled off the road, stuck my head out the door, and looked up, before making a U-turn, but that was the best you could do pre-GPS navigation) and used it to find Notre Dame.

I’ll show it to Lilah when I get home. “Hey Lilah, that star is called Reguls and I could see it from Parisfrance” and she might find it wonderful and mysterious and amazing that you can see the same thing from such different places. Or she might ignore me and say “Daddy Daddy I’m going to draw a picture of a ghost for you” or who knows what else. But I will remember that it is wonderful mysterious and amazing that that’s the same star that showed me which direction to turn on a tiny street after midnight in a big city halfway across the world.

[next week: a name for Orcus's moon. I haven't had a chance to read any of the suggestions yet (being on vacation in Paris), but I see that there will be many many to chose from. Stay tuned.]

To the moon

My father was a rocket scientist. Well, OK, not precisely. More specifically he was a rocket engineer. Or, more precisely still, he was an engineer who worked on the computers that went into space and navigated the rockets. He worked on the Saturn V that lifted Apollo astronauts toward the moon, he worked on the Lunar Module, which touched down on the moon, he worked on the Lunar Rover, which drove astronauts around on the moon. All of this before he was 30 years old.

I never remember him talking about it at all, talking about what it was like to send men to the moon, to be involved in such a tremendous adventure, but, ten years ago, in the little farming town on the edge of the Mississippi River where he grew up, I had a conversation with one of his friends from those days, and he told me that they all felt like they had lived in a magical time. After the Apollo missions ended, they all later worked on the Space Station and more mundane things like the ticket-taker on the BART trains that I used to take when I was a graduate student living on the San Francisco Bay. But nothing in their lives was ever quite like a being a bunch of thirty-year-old kids living in northern Alabama having the blind optimism to think that if there was a rocket being built they knew enough to put the computers together to make those rockets bring people to the moon. And back. And then actually doing it.

I wish I could ask him about it, but that opportunity is a decade gone.

Being the mid nineteen seventies, he had a marriage and he had three children – me, my older brother Andy, my younger sister Cammy – all before he turned 30, and we all lived in what now seems to me like a huge house in northern Alabama. Being the mid nineteen seventies, the marriage didn’t last. He moved to an apartment across town, then to Maryland, then to North Carolina, then to Houston, and finally, for his last few weeks, back to North Carolina to stay in the house of my sister.

In those last few weeks my brother and I were there at my sister’s house, too. I was in the middle of my third year of being a professor at Caltech and I was still trying to get on my feet. But, that quarter, I simply canceled my class midway through and gave everyone in attendance an “A.” Oddly, I had no complaints. I then flew across the country to meet my father and my sister and soon my brother and we all stayed in North Carolina for a while.

It was too late then to say much. He was mostly groggy from the pain medication. But we talked some about what was happening in all of our lives. Though he never would say such a thing directly, I think he was proud that I done well enough at school to land a job being a professor at Caltech. I remember complaining about some of the more mundane aspects of the job to him and having him softly glare back and whisper: “do you know how lucky you are?”

I told him about a new project I was starting that I was quite excited about. We had just started using an old telescope at Palomar Observatory to make repeated wide-field observations of the night sky in search of particularly large objects in the outer solar system. I told him that I was certain there would be things larger than Pluto out there to see and that I really hoped to be the one to find them. He always liked long-term plans and was happy to see that I finally seemed to have one. “But what if there isn’t anything out there?” he asked, in his always not-quite-so-encouraging way. There will be, I said. I’m sure there will be.

We talked about the long term relationship I was in that, though I didn’t know it at the time, was within a month of finally falling apart. I told him why the relationship was hard and not going so well. I remember perhaps the only words of relationship advice he ever gave me: “There shouldn’t be any fighting. Find someone you don’t fight with.” Though the words resonated with me, my father’s accumulated lifetime credibility in this realm was not high. So I filed the advice away.

He died a few days later. It was ten years ago today.

I’ve missed not having a father for the past decade. I feel we were still, that late in both of our lives, getting to know and understand each other, something we had never had much of an opportunity to do when I was younger.

But, today, I am thinking of the things that I wish I had the opportunity to show him over the past decade. I don’t have much in the way of spiritual beliefs about any afterlife, but, if there is one, and the deceased person can pick his form of communication with the corporeal world, I am pretty sure that my father would pick the web. When he first got cancer nearly 20 years ago he immediately took to the then-new internet as a means of educating himself and everyone else about everything to do with the cancer, the treatments, the options. It’s the sort of thing that everyone does routinely these days, but, back then, it was still quite novel. So if he’s out there anywhere, I like to think of him hooked in through some vast astral server. So this is for him, vial HTML, which he first introduced me to:

Dad –
A lot has happened in the past decade that I think you’d have been proud to have heard about, but there are three that I really wish I could share with you.

Remember that project I told you about ten years ago? The one that started looking over vast swaths of sky for things that moved? The one where I thought I would find another planet? Well, it took a few years before it began paying off, but it has been a pretty spectacular ride. There were indeed things out there to be found. One – so far – was even bigger than Pluto. I wouldn’t have guessed at the time, but all of it caused a big shakeout in the solar system leading to the new decision to recognize only 8 planets. That’s a pretty big change from your lifetime, where Pluto was a planet when you were born and Pluto was a planet when you died. I think you would have enjoyed watching the changes happen. And I sort of suspect that, though you would never actually say it directly to me, you would be somewhat proud of me. I’m sorry you weren’t around to see it.

Some other big news of the past decade: you were right about relationships and fighting, I think. Who would have guessed that? It took me another four years after that conversation, but I did find that person you were trying to guide me towards. I got married to Diane six years ago. I know that you were perhaps always convinced that no one was ever good enough for one of your kids, but, I have to admit, I think you would be charmed. I look at the picture that was taken on our wedding day sometimes, the one that has Diane and me and my brother and his wife and my sister and her husband and their two kids and my mother and my step-father and I wish that you were in the picture too. It would have been a bit awkward, these extended family things always were, but the awkwardness would have been better than the empty spot that I now see every time I see that picture.

There’s one more thing I wish I could show you. Her name is Lilah, and she is a 3 ½ year old bundle of silliness, stubbornness, curiousness, sweetness, and talkativeness. It is part of the mythology from my childhood that you were not particularly pleased about having that third child, but when it turned out to be a baby girl you pretty quickly got over your misgivings. I think you would like Lilah, and I think it would be pretty hard for you to hide. She asks about you sometimes. She asked about you this morning, even. “But Daddy, who was your daddy?” and I tell her about you. “Why did he die?” she asks. I explain about being sick, about having cancer. She understands a little, but, clearly, only a little. “Do you get another daddy when yours dies?” No Lilah. You never do. You never, ever, do.

What Lilah doesn’t yet know is that you don’t want another daddy when yours dies. You just want yours back. And when you realize that that is never going to happen, you at least want a chance to tell him a few things. And you hope that he has some chance of listening in, at least every ten years or so.

Lilah Brown's Planets, Part II (or, Season II preview)

Friday night my wife and my 3 ½ year old daughter Lilah picked me up at work to go have some dinner. When I opened the car door, Lilah, who it appears was about to explode from waiting to tell me something, blurted out “Daddy, daddy, daddy LOOK!” and pointed off to the west with an excited look in her eye. I followed her finger to a spot above the horizon where a thin sliver moon was shining down with Venus just a finger width to its right. “It’s Venus and the moon,” she breathlessly exclaimed, “and the moon is little but it is pretending to be full,” her words to describe the ghostly outline of the full moon seen in the background of the bright glint of the crescent moon.

“Daddy daddy daddy do you remember when we saw Venus and the moon and Jupiter, too?”

I do indeed remember that. That moment was the December crescent moon, three full lunations ago. It was also the moment that I like to think of as the final episode of the first season of Mike Brown’s Planets. Like any self-respecting TV production, I’ve been taking a summer hiatus. It’s just that my hiatus occurred during southern summer rather than northern summer.

I’m not sure what TV production crews do during a hiatus but we’ve been pretty busy here at Mike Brown’s Planets, doing a bit of science. You’ll get to hear all about it in upcoming installments. Some of the highlights upcoming include:

Name a satellite of a Kuiper belt object! I’ll tell you about the Kuiper belt object and its satellite and then I’ll take suggestions of what to name the satellite (and why). The best suggestion will get forwarded to the IAU as the official recommendation.
Life, death, and the Kuiper belt.
More and more and more moon shadows. Last season readers here were the first to hear about the ongoing shadow crossing of Haumea by Namaka (and why they are both important and cool). Much much more is to come (and you can read more about it in an ongoing technical blog intended more for research astronomers, but, nonetheless, occasionally entertaining)
My father, rocket scientist, RIP
A (slightly belated) look forward at discoveries that might be made in 2009 and a look back at the 2008 predictions to see how many, if any, came true.
Why Pluto is still not a planet and should remain that way.
Things in the sky that make me smile.

Stay tuned for Season II!

Lilah Brown's Planets

Since late summer, my three year old daughter Lilah has been mesmerized by Jupiter. Every night for a few months now it has been high in the evening sky, one of the first things to pop out of the murky twilight and reveal itself night after night after night. Back in the summer we would have to go outside right at her bedtime, when it was just barely dark enough to make out Jupiter, so she could say good night. These days it is plenty dark as we drive home every day, and , for her, the highlight of the drive is the moment after we’ve climbed the little hill to our neighborhood and we take the final left hand turn to point west, and Jupiter suddenly appears in her window, high enough in the sky to even be seen from the moderate depths of her child car seat.

Anyone who, like Lilah, has been following Jupiter has noticed that it is no longer the king of the evening skies. A while back Venus crept up into the twilight to start to steal the show from Jupiter. Or, at least, in Lilah’s view, to share the show. She went from having only one planet to now having two planets to say goodnight to every night.

Lilah sees planets everywhere. You never quite realize – until you have an obsessed 3 year old – how prevalent images of planets are in everyday life. She’s got them on her lunchbox (a gift from friends who thought it would be funny if Lilah carried a lunchbox where Pluto is a planet); she sees pictures in magazines and catalogs; she sees mobiles and puzzles at stores. I would tend to just walk by them without noticing, but she always runs up – “Daddy daddy daddy daddy LOOK!” She always quickly picks out Jupiter (the big one) and, of course, Saturn. She recognizes the globe-like look of Earth. And she gets Venus right more often than I think she should.

A few nights ago, after a long cloudy spell when we couldn’t see the planets at night, Lilah looked up at the sky and was a bit startled. “Daddy daddy daddy daddy daddy daddy daddy LOOK! Jupiter MOVED!’ And she was right. While Venus and Jupiter had been slowly edging closer to each other over the past few weeks, you wouldn’t notice it unless you were watching closely. But now they were suddenly so close that even a three year old could look and see that something had changed.

As much as I am charmed by Lilah picking out pictures of planets in magazines to show me, having her point out to me that Jupiter moved was – for me – the pinnacle of planetary charm. While most kids and adults can name the planets and point out pictures, almost nobody notices the real thing even when it is blazing in the evening sky. Planets are not just things that spacecraft visit and beam back pictures from. They’re not just abstractions to put on lunch boxes. They are really there night after night after night, doing what only planets do: moving.

Last night – Saturday – the show got even better. The sliver moon showed up low in the early evening sky anda began working its way toward Jupiter and Venus. For half of the month, Lilah and I watch the moon get bigger and move east night after night in the evening sky, so we both know what is going to happen next. Based on how far the moon is from Venus and Jupiter, it looks like on Monday night the moon will be packed tightly in the evening sky with Jupiter and Venus. It will, I suspect, be a spectacular sight, with the three brightest objects ever visible in the night sky in an unmistakable grouping in the southwest just after sunset. It’s the sort of site that I think – that I hope – will make even non-night sky watchers suddenly look up and wonder. And when they look the next night, to see if it is still there, they will notice the moon has already moved further east and gotten a little bigger, and they will see that two other bright lights – Jupiter and Venus – are in slightly different spots. Maybe even a person or two will follow the moon’s movement for the next week as it grows to full. Maybe a lucky few will watch as Jupiter gets lower night after night, leaving Venus alone in the sky by next month. It’s a show worth following. I know Lilah and I will.

I’m on a flight across the country tonight. I touch down long after Jupiter and Venus and the Moon will all have set in Florida. As I was packing my bags this morning Lilah asked: “Daddy, are you going away to go talk about planets?” Yes, Lilah. I’m going away to talk about planets. I forgot to tell her, though, that I’m going to see some, too. I was sure to pick a window seat on the south side of the airplane so I could watch the show from the air. And when I arrive I’ll call back home and tell Lilah all about it and tell her to go outside right now and LOOK! she can see all of our favorite planets and LOOK! the moon has moved and grown and I’m sorry that planets are taking me far from home tonight but I’m glad we have these here in the sky to share tonight and forever.

Moon Shadows, Interruped

I had intended today to talk more about moon shadows and telescope strategies, but I'm distracted by Google Earth, satellite weather images, and LA Times updates.

Yesterday as I stepped out of the gym on the Caltech campus in the middle of the afternoon (Lilah's nap time is a good time to play squash), I looked up at the sweeping view of the mountains that greets you in many places in Pasadena. This time, though, the first thing I noticed was a plume of smoke coming out of a canyon to the northeast. Which canyon? I quickly zoomed in on some of the familiar ridges and valleys of the San Gabriels to figure out exactly how far away the fire was. How far the fire was from my house where Diane was home, Lilah was asleep. As far as I could tell, it was about 5 miles to the east of our house. Five miles is a long distance for fire on a day when the wind is essentially still. But still. I dropped my gym bag, fished through it to find the phone, and dialed home. Diane answered.

"Where's the fire?" I breathlessly asked.

"Um, what fire?"

This answer was probably the best she could have given. I now more calmly explained to her what I was seeing.

I got in the car and drove back to home. On the freeway you had a nice view, now, of a burning ridge. This fire was definitely not a little spot fire that was going to quickly get put out, but from there I could tell it was pretty far from our house. When I got home I pulled up Google Earth and tried to reproduce the exact view I had had from the freeway. I showed Diane. There. That ridge. Pretty far away.

Last night we had friends over for dinner and, as they got close enough to our neighborhood to see flames a few miles away, they called to say "Hey, isn't that fire kinda close to your house? Maybe we should have dinner at our house instead."

It was OK. Nothing was really close. I surreptitiously went inside now and then to check on the news web pages to see if anything was going on. Not really. Some hikers had to be evacuated. Some boy scouts had been temporarily trapped. The fire would be contained soon. I checked the satellite weather image, on which you could see the plume of smoke heading out to sea. It looked undiminished.

This morning we awoke to something now familiar. As night falls and air cools, the ash that has been lofted into the air all day long falls to earth. The ground was covered in gray flecks and bits. The smell of smoke had invaded the house through the windows we had kept open all night. The sun, rising to the east, on the other side of the fire, made a hazy red glow on the wall of the canyon we could see from our bedroom window.

The helicopters started early. We hadn't seen too many yesterday, but now there numbers were definitely increased. Fire trucks went screaming down the road below us.

Curious to see how far the fire had spread, I took Lilah -- still in pajamas -- and drove down the hill in the direction of the smoke. Whereas yesterday the fire was easily spotted and sharply defined, it was now tough to see anything through all of the smoke. I couldn't tell where it was, but I could tell it had grown overnight.

Sunday plans must go on. Diane had a work event and left. Lilah and I went swimming under the hazy sun. We ate grilled cheese sandwiches, played with finger puppets of the three little pigs, did a little roving hide and seek throughout the house, and finally Lilah went to sleep for her nap. Curious about the fire, I looked to see if I could find any news.

I guess there was a reason for all of the helicopters and firetrucks that seemed so close by. Houses were being evacuated. The fire was still out of control. I got out Google Earth once again to try to interpret what I read. The evacuations are all in the upper part of the city of Sierra Madre, the city immediately to our east. When I finally found the evaculation map I realized that houses 1 1/2 miles from ours were already evacuated.

It's not really that close. But still.

This time it was Diane's turn to call: "I just heard Sierra Madre's been evacuated; should I come home?"

"No. We're fine."

And we are. Really.

We live in a fire zone. Our house overlooks a wild canyon that is right now gloriously flowered, but come the hot winds of the summer and fall will be dead brown fuel. We do what we can. Our roof is fire resistant composite. We thin vegetation. Our swimming pool is connected to a fire hydrant on the street so that a fire truck could easily use the water to douse our lower neighbor's house (but not ours; it's only gravity fed, so it could only help the people below us; sadly, the house above us has no pool that would help us out similarly).

We have evacuation plans with multiple contingencies. Distant fire with plenty of time to plan? Pack both cars and take this this and this. Fire in the canyon right below our house? Take Lilah first, cats if there is time, and run like hell. What if the only road down the hill already has been overtaken? There is a trail behind our neighbor's yard that quickly goes down to a safe spot. Fire on all sides? Jump in the pool and breath through wet clothes.

We won't need any of these plans for this fire. They'll have it out tomorrow or the next day and, more likely than not, nothing significant will have been lost. It's the springtime. It's early. The plants still have some moisture left in them. The winds are not blowing. The real fire season has not yet begun.

These sorts of fires happen all the time in southern California. It will likely not rate more than a 4th page of the local news blip in the LA Times tomorrow morning.

But still. Right now Lilah remains soundly napping. Diane is at work wondering what is going on, and all I can do is sit and check the news sites, watch the helicopters to see how close they drop their loads of water, and stare at Google Earth and speculate on the interaction of slope direction, wind speed, and fire vectors.

Someday, presumably, it will be more. Plans will be put into action. We'll sit below with binoculars staring up at the hillside trying to figure out how close the flames have gotten. We'll call our home telephone to see if the answering machine picks up. For now, though, we do what we can, hope for the best, and always breath a little easier when the winds don't blow.

Tomorrow normal life will continue. Which, for me, means dealing with the technical aspects of our upcoming observations of the Hubble Space Telescope. Our proposal to search for moon shadows on Santa was accepted on Thursday, and observations will start in 2 weeks. That's what meant to write about today, before being interrupted by smoke and helicopters and fire.

Tiny Bunnies

This morning my 2 ½ year old daughter Lilah opened the front door to find the tiniest Easter basket I have ever seen, filled with candy, bubbles, and stickers. My suspicion, as yet unconfirmed, is that Easter baskets everywhere were equally tiny today, and that it is all the fault of the moon.

This is the third Easter Diane, Lilah, and I have spent in our house up in the foothills above Pasadena. After last year’s record low rainfall, Easter – and springtime in general – was marked by an intensifying of the brown in the canyon in our backyard. That same brown all over southern California contributed greatly to the intense wildfires that swept the region last fall. The small-scale wildlife that was abundant in our backyard two years ago – rabbits, squirrels, even the occasional bobcat and [once] black bear – generally disappeared.

This year the occasional torrential rains typical of southern California winters returned and gave everything a nice soaking. The canyon in our backyard is awash in green and is about to explode into a sea of yellow mustard flowers. Even the great canyon oaks which dominate the canyon and are designed for long term droughts have a fresh sheen from the first set of new leaves in two years. Squirrels have been running around chasing the droppings of the bird food we keep out for the finches and sparrows and blue jays and titmice. Some as-yet-unknown small animal sneaks through the fence around my garden and has been nibbling on the leaves of the artichokes. The first sweet pea pods are forming. Lilah has a small box with caterpillars waiting to change into butterflies and a small bucket with tadpoles waiting to change into frogs. With the equinox passing just two days ago, it certainly feels like spring has come.

But the bunnies? Two year ago, our first Easter, the connection between Easter and bunnies was obvious. They were everywhere. You couldn’t open a curtain or door in the morning without stumbling on a new set of bunnies nibbling on the bushes, hopping down the street, playing in the grass. It was easy to explain to Lilah that the Easter bunny was certainly on his way. This year, though, the bunnies are almost unseen. One or two tiny babies have been spotted, but not the abundance of two Easters ago. What is going on?

I think the fault is not with the bunnies, but with Easter. Easter is awfully early this year, and it is likely that no one told the bunnies to start earlier. Two years ago Easter was on April 16^th, a full three weeks later.

The bunnies should, of course, be watching the sun and the moon to know when Easter is. This year, in particular, with Easter so early, the method of choosing the date of Easter has been much in the news. Easter falls on the first Sunday after the first full moon after the Spring Equinox. The Spring Equinox is, of course, the precise midpoint between the long night of the Winter Solstice, back in December, and the eternal twilight of Summer Solstice, in June. On the Equinox, the day and night are of equal duration (the origin of the name) all around the planet. Also, the sun rises and sets directly east and west. Thus, one way to know that the equinox is near is if, like me, you live in a town where most streets are on a north-south-east-west grid, you will start to notice that the sun is always setting (or rising) precisely in your eyes as you head westward to go home at night (or eastward to leave home in the morning). That means the equinox.

Even the equinox occurred a little early this year. The precise moment when the sun was precisely over the equator (another way to define the equinox) was 5:48AM GMT on March 20^th, which translates to 10:48PM PDT on March 19^th here in Pasadena. Last year it was 5:07PM PDT on March 20^th. In reality the equinox didn’t change, just our calendar. With leap year this year our calendar is behind by almost a day. It will catch up again over the next 4 years.

The full moon, which could come at any time over the next four weeks, happened to follow closely this year, occurring at 10:40am on March 21^st. And it was a Friday, so the next Sunday was only 2 days later. Today is March 23^rd, and it is Easter. The bunnies could have gotten it right by watching to see when night and day were equal lengths, looking for the next full moon, and watching driveways everywhere for an extra fat morning newspaper to know it was Sunday and thus Easter.

Except that this is not really correct. I used to imagine teams of astronomers sitting around with precise measuring tools to declare when the equinox had occurred to set everything in motion. I used to smugly explain all about astronomy’s role in determining the date of Easter to anyone who would listen. I used to wonder if it ever happened that the full moon followed the solstice by minutes and made for instant Easter. But, this year, I finally looked up who really decides. The answer is a bit disappointing, at least to me. For the purposes of Easter-determining, the equinox is on March 21^st. No astronomer needs to track the sky; we can all just look at the calendar. The precise moment of the full moon? Not actually important either. Officially, centuries old calculations are used, which differ from the actual date of the full moon by up to two days.

Still, I could at least be smug in my amusement that yet again a major Christian holiday had clear ties to early astronomy and astrology and was designed to co-opt some sort of Pagan equinox celebration. Except, when I read more, I realized even that was not true. The timing was an actual attempt to figure out an actual date of the Last Supper, for which there is some indication that it was slightly before Passover. Passover, in the Hebrew calendar, occurs on the 15^th day of Nisan. The first day of a moon was originally declared to occur when credible witnesses had seen a crescent moon. Nisan, which approximately translates in Babylonian as “until the barley is ripe,” was declared based on the critical springtime crop. It occurred around the time of the equinox. Fifteen days after the start of Nisan the moon would be full. And Passover would begin, on the day of the first full moon after the equinox.

So my smug amusement is totally misguided. Instead I should have understood and respected the observational, agricultural, and astronomical aspects of the much older Hebrew calendar. It is quite amazing that such a calendar designed thousands of years ago still underpins the basis of the day of one of the larger religious holidays of the year. But even with my newfound respect I can see the problems. The bunnies, even if they knew the astronomical rules, could never read all of the ancient tables. They will never know ahead of time when Easter is here. And occasionally, when the moon is right (and the tables are right too), Easter will show up weeks too early and then bunnies will not have grown. Easter baskets everywhere will have to be downsized so the tiny bunnies can carry them to front doors.

Luckily for me, at 2 ½ Lilah doesn’t yet know what she is missing. But next year, as a 3 ½ year old, she may catch on. Happily, next year, Easter is not until April 12^th, and, once again, the bunnies will be running all around the yard, hiding candy and eggs as they go.

Five good years

Five years is a long time.

Five years ago this month there was a major scientific conference in Chile on the Kuiper belt. Astronomers from all over the world converged on a small coastal town to discuss what was know and what might be learned in the future. We knew a lot about the Kuiper belt then. Or at least we felt we did. But what a difference five years have made.

Five years ago Quaoar was the largest known Kuiper belt object, and we counted Pluto as a planet. Today Quaoar is not even in the top five, and Pluto is not a planet, but just the second largest Kuiper belt object.

Five years ago the most distant object that had ever been seen was an otherwise obscure Kuiper belt object with the name 1999DG8. It is 61 times further from the sun than the earth is, in what seemed like the outer fringe of the solar system at the time. Today we know that Eris is much further away (90 times further than the earth), though it is soon going to work its way in close. But we also know about Sedna, which we would have never predicted. Sedna is currently just a little closer to the sun than is Eris, but, soon, it will be on its way out. At its most distant, Sedna is about 1000 times the distance from the earth to the sun. Sedna takes about 12,000 years to go around the sun; the last time it was this close to the sun the earth was working its way out of the most recent of the ice ages. I often wonder what will be happening on the earth the next time Sedna comes around, in the year 14,000 AD.

Five years ago, no one sitting at the conference in Chile would have ever guessed that we would eventually find an object like 2003 EL61 -- aka Santa -- the fast spinning elongated Kuiper belt object that we now know to be the product of massive collision in the outer solar system perhaps 4.5 billion years ago. And people would never have believed that we would even be able to find many of the shards from the impact and start to be able to reconstruct the original humpty dumpty.

One thing that would not surprise anyone from five years ago is that we finally found something bigger than Pluto. Most people studying the Kuiper belt assumed it would eventually happen, and I think many were finally relieved when it happened. No one could have known, of course, just how crazy the year-long debate about planets would be, but I think most of the people at the conference five years ago were pretty convinced that eventually we would fix the classification of objects in the outer solar system by placing Pluto in its rightful place with the rest of the Kuiper belt.

It was a fascinating conference five years ago, I am told. But I didn't have the chance to go. I was, by chance, also in Chile during the conference itself, but I was not sitting in an auditorium in the north of the country with my fellow astronomers, I was hiking in the southern Patagonia regions with my wife. My then-brand new wife. We were on our honeymoon. We got married on March 1st, 2003. Five years ago today. Five good years.

[disclaimer: it is still significantly proposal season, so this column only counts as procrastination when I should be working on a proposal instead.]

Jupiter years

I saw Jupiter this morning for the first time this year. It was sitting low in the pre-dawn southeastern sky, just above where the tea pot that is Sagittarius should have been if the sun were not already making most of the night sky disappear. It made me think back to 1996, when I had just moved to southern California to start work at Caltech, to 1984, when I had just moved to New Jersey – a state which I had never before even visited – to go to college, and to 1972 when I was a seven year old listening to the sounds of the Saturn V rocket being tested across town.

The first time I see Jupiter for the year always takes me back in these twelve year leaps because Jupiter takes twelve years to go around the sun and thus return to appearing in the same constellation – this time Sagittarius – once again. So in thinking back to 1996 I am thinking about where I was a Jupiter year ago. And, unlike earth years, Jupiter years are long enough that, for me at least, a Jupiter year always takes me back to a place in my life when everything was totally different from today. It’s also hard not to think a Jupiter year forward in time. The year 2020 seems a long way off, but it is really only a year away.

For the last few months, Jupiter has been up in the sky during the daytime and couldn’t be seen, but, as the earth has moved around the sun and the seasons have turned, the constellations that could be seen at night have slowly shifted until Jupiter made its first appearance in the morning twilight sky before the rising sun extinguished it. Something that appears in the early morning sky will, a few months later, appear in the midnight sky, a few months later in the evening sky, and a month after that be setting with the setting sun to appear again in the morning half a year later. When I first see Jupiter in the early morning I always think that “Jupiter season” is just starting. When I was younger I would be likely to get my first glimpse of Jupiter for the year in the early morning after staying up late working or playing. These days I am more likely to first see Jupiter for the year in the pre-dawn sky on my way to the airport to catch an early flight. Such are the seasons of a life.

While I was in graduate school in Berkeley the subject of my Ph.D. dissertation was Io, the volcanically active moon of Jupiter. During this part of my life, Jupiter season meant it was time to get to serious work. My dissertation involved spending many months at the telescope during Jupiter season watching Io and its volcanoes and its atmosphere and trying to disentangle what was causing what to do what and how. The first appearance of Jupiter in the early morning sky was always a visceral jolt that I needed to be ready for the season to come.

The winter and spring of 1991 – 1992 were to be the most intensive Jupiter season of all for me and were going to be the culmination of my study of Io and the main basis for my Ph.D. dissertation. The summer before the observations were to begin, however, Jupiter season was far from my mind. My uncle had just been casually killed for the few hundred dollars he carried into a bar one night, and soon thereafter my ailing grandfather slipped, fell, and died. I flew to Colorado to drive with my brother to the funeral in New Madrid, Missouri, on the shore of the Mississippi River. He picked me up at the airport and we drove all afternoon across Colorado and then continued through the night across Kansas talking about family and backpacking trips we had each made that summer. We made Missouri just before the sun was about to rise. Driving east trying to stay awake with my brother finally asleep in the front seat I looked up at the sky and just rising before the rising sun was a bright star sitting just below the feet of the lion in the constellation Leo. It hadn’t been there a year before. It was Jupiter. It was Jupiter season. Regardless of whatever else was to come, Jupiter was in the morning sky and its season was on the way.

Twelve years after my grandfather’s funeral Jupiter would have spun all the way around the sky and been back at Leo’s feet again: a Jupiter year. But my father didn’t make another Jupiter year. Eight years later we were all back in New Madrid, Missouri for my father’s funeral. I had driven from my sister’s house in North Carolina to Missouri this time, my brother and I in my father’s pickup, my sister and family in the minivan behind, and, driving through the day and even into the night we never saw any planets.

Friends of my father from around the county and around the country came to the funeral and we decided to have a story-telling and rum-and-coke (the drink of choice on the small trawling boat that my father lived on the last few years of his life) drinking session late into the night. We heard stories of sailing trips, late night driving to Florida interrupted by stopping to refurbish the brakes on the side of the Interstate, childhood stories of driving across fields plowing down fence posts, but the story that I remember best came from a friend who had worked with my father in the Apollo days in Huntsville, Alabama. He said that he and my father had talked recently and had spent much of the time reminiscing about that amazing but short period between 1969 and 1972 when they worked designing and constructing the computers that controlled the Saturn V rockets as they hurled men into space and onward to the moon. They had been thirty year old young men with wives and families at home and they had gone to work and figured out how to get the job done and they had sent a man to the moon.

It’s been 3 Jupiter years since the last man left the moon, and not quite 1 Jupiter year since my father’s funeral. In another Jupiter year I will be exactly the age that my father was when he was first diagnosed with the cancer that eventually killed him. I hope, though, that I am given the chance to see Jupiter round the sky a few more times before the end.

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