A thoroughly sporadic column from astronomer Mike Brown on space and science, planets and dwarf planets, the sun, the moon, the stars, and the joys and frustrations of search, discovery, and life. With a family in tow. Or towing. Or perhaps in mutual orbit.

Showing posts with label IAU. Show all posts
Showing posts with label IAU. Show all posts

Free the dwarf planets!

 Most people will probably think of tomorrow as the 5 year anniversary of the demotion of former-planet Pluto. That seems fair; the Pluto demotion got all of the news, caused all of the fights, and promoted all of the discussion. But now that tempers have cooled and the world has come to terms with a new more scientific eight-planet solar system, it is time to remember the other important thing that happened on that day five years ago. On August 24th 2006 the International Astronomical Union (IAU) defined a new class of objects in the solar system: the dwarf planets.

As you will recall, the IAU declared that planets are the objects which go around the sun and gravitationally dominate their orbits. In our solar system, the eight planets are unique in that behavior. But there are other much smaller bodies out there – Pluto being the most famous – that look like planets (simply meaning that they are round) but are not dominant. Pluto and many of these other objects all circle the sun in similar orbits in what is called the Kuiper belt. These objects are the dwarf planets.

At the time this new class of dwarf planets was proposed, the IAU also declared that three dwarf planets were then known: Ceres (the largest asteroid), Eris (the newly discovered largest Kuiper belt object which precipitated all of this mess), and Pluto. In the entire five years since then, the IAU has declared two other objects to be dwarf planets: Makemake and Haumea.

A reasonable person might think that this means that there are five known objects in the solar system which fit the IAU definition of dwarf planet, but this reasonable person would be nowhere close to correct. By my best estimate there are possibly 390 known dwarf planets in the solar system (don’t worry, I’ll explain below).

What is going on here?

Rio roundup

Last week I wrote about the International Astronomical Union (#IAU) General Assembly taking place in Rio de Janeiro, to which I was headed. Most people, if they even ever heard of the IAU only know it for its role in the demotion of Pluto at the last General Assembly three years ago. Even I was not entirely sure what to think. I’m not a member of the IAU (mostly because I have never quite gotten around to filling out some form at the right time) and had never gone to one of the General Assemblies before (including the infamous one three years ago where Pluto was discussed; I was instead on vacation in the San Juan Islands outside of Seattle). I have had my share of frustration with the IAU bureaucracies in everything from the stupidity of the way they originally tried to ram Pluto-as-a-planet down the reluctant throats of astronomers (to which the astronomers, who will thus always have my admiration, revolted) to their ridiculousness of their official list of dwarf planets (I will rant about that at a later date, no doubt), to their shameless lack of interest in resolving – one way or another – a case which was either egregious scientific fraud (against me) or equally egregious scientific bullying (by me).

My intention in Rio was simply to go to the special scientific sessions on Icy Bodies in the Solar Systen (somewhat of a specialty of mine) and avoid any IAU-ness. In my mind it was simply yet-another large scientific meeting, this time spread over too much time (two weeks! far too much time to take away from the family), and too many topics (the solar system to the edge of the universe and everything in between and then more). I went, though, because I had been invited to give an extended talk on dwarf planets, and because I thought there might be Pluto shenanigans that I didn’t want to miss out on this time.
I think it is fair to say that I went in with a bad attitude.
Reflecting about all of this on the flight home this morning my main reaction is a little bit of sadness that it took me two or three days to come to the realization that there were amazing things being talked about in every little corner of the IAU meeting. Yes, I learned about icy bodies: the delivery of water to the early earth, the potential interior structure of Titan, the presence of things that look like comets in places that should be reserved for asteroids. And I got to ask some colleagues a few key questions that had been nagging me. (Is it possible that in the early solar system things from the Kuiper belt got mixed out to the asteroid belt? I, unfortunately, was told “no.” Scratch one idea I had off the board.) I even got to finally meet some colleagues from Brazil and Uruguay who rarely get to travel to major meetings, and we talked about future projects we might do jointly.
All of this was good, but not the part that I am flying home most excited about. I am most excited about the incredible number of people who were at the meeting who were enthusiastically and dedicatedly going to talks about astronomical education, about astronomy in developing countries, about preserving the night skies, about using 2009, the International Year of Astronomy (IYA), as a platform for building and keeping the momentum of public engagement. There were posters with pictures of IYA activities in every country I had ever heard of (and even, I will admit, a few countries that I had to ask, um, exactly where they were). And the people doing all of this just seemed beyond themselves with the excitement of astronomy. None of the typical scientific meeting snarky chatter of “well, sure, that was an OK talk, but really he should have cited the work of her and him and them” or “possibly interesting, but I don’t think I would be willing to jump to such a conclusion with such shoddy data” or “let’s not bother waking up early to hear that same talk of her’s yet again.”
It’s great being a professional astronomer and a professor. It’s hard to imagine any job that I could have that I would enjoy more. Yet, regardless of how much I love what I do, there are aspects of it that are simply a job. And like any other job there are parts that get tedious. And like most other people, when parts get tedious I get cranky. My Ph.D. students at Caltech have figured this out quite well. One of the necessary evils of being an astronomer is having to write proposal after proposal after proposal, and, according to the lore passed down from student to student, I become quite irritable approximately two days before any proposal is due. They know that it is best not to come into my office with a seemingly trivial question at times like that.
As an antidote to crankiness about the job of astronomy or about the bureaucrats of the IAU, I’m keeping my program from Rio with the names of all of the talks and all of the posters from everywhere around the world. Long after I’ve forgotten what I in the invited talk which was the reason I went (“Haumea and her children” was the title, if you must know), I want to still remember all of those people so excited by everything astronomical that they devote their lives not to discovery but to showing it to everyone else.
Concrete [I hope] postscript:
OK, I’m not just going to keep the program booklet, I’m going to try to get into the act. I had a long conversation one evening with an inspiring woman who is involved in more interesting things than I can imagine but who appears particularly excited about bringing astronomy to parts of Africa where there is little to none. She wants to try to set up asteroid-naming art projects for African school children. I can provide asteroids that need names; she knows what to do in Africa. I say hey, @carolune, let’s go. Stay tuned….

Don't try to blame it on Rio

Three years ago, in Prague, astronomers had perhaps the most contentious gathering in modern astronomical history. Usually the International Astronomical Union meeting is nothing but a once-every-three year's chance for astronomers to advertise their latest discovery or newest idea while spending some time in a nice international destination, having dinners with old friends and catching up on their celestial gossip. On the final day of each meeting, in a session attended by almost no one, resolutions are passed, usually all but unanimously, on such pressing topics as the precise definition, to the millisecond, of Barycentric Dynamical Time (I have no idea what this actually even means, but, presumably, it matters critically to someone).
The meeting three years ago was different. The usually placid astronomers had spent their time in Prague arguing and bickering day and night about Pluto and about planets and about how to reconcile the two. While several of the typically unintelligible resolutions were indeed to be voted on this last day, the final two resolutions would be all about Pluto. The usually sparsely attended final session was full of surly astronomers itching for a fight.
Everyone by now knows the outcome. In an overwhelming vote, astronomers agreed to tighten the definition of the word “planet” to mean, essentially, the large dominant things in the solar system. Which Pluto is not. That was the end of Pluto as a planet. That was the end, too, of Eris (the slightly-larger-than-Pluto iceball that I discovered that had precipitated the mess) as a planet.
The solar system makes more sense now, and, in three years most people have come to terms with the new solar system. But not everyone (as an example, read the inevitable comments soon to follow this post….).
Three years ago, when the vote put Pluto into its proper place, some vowed to carry the fight forward. “Onward to Rio!” they cried.
It’s three years later, and it is time, once again, for the Internation Astronomical Union meeting, this time in Rio de Janeiro The meeting. It starts tomorrow and I am currently staring out across Copacabana beach watching the winter waves pound the shore (Winter? Only sort of. The beach is packed and the clothes are skimpy) waiting for the real fireworks to begin.
But will there be any? There is an entire weeklong program called “Icy Bodies in the Solar System” with talks about the Kuiper belt, comets, icy satellites, dwarf planets, and even one talk about Pluto. But nowhere is there slated to be any official discussion about Pluto. Will it happen anyway? Will the partisan defenders of Pluto try to storm the meeting in protest to finally have their day in court?
It would be the right forum, for sure. Because of the special program, many of the astronomers who think deeply about planets and the outer solar system are here. Why not ask?
I predict that by the end of the week, the topic of Pluto and planets will come up, at best, only outside of the actual meeting over a few glasses of caipirhina. I suspect no one will press the fight about Pluto because even the partisans are reluctantly admitting to themselves that the fight is over and planets have won.
After the vote three years ago the Pluto partisans tried every trick and argument they could come up with to convince people that the IAU vote had been ill conceived or procedurally wrong, or poorly attended or anything else. All of that could have been fixed by now and a new vote could be taken. Except that Pluto would lose again. And new excuses would be needed (how about: the moon was full and astronomers became lunatics!).
Will they actually give up? I suspect not. It’s easy enough to keep the controversy alive in the media long after most serious scientists have moved on to better things. But I think the fighting will all be guerilla style these days.
But don’t give up hope! Perhaps something will unexpectedly spill into the open and Rio can turn into a place as fun as Prague. Stay tuned….
For entertainment, and should anyone care, I am (sigh) tweeting the IAU meeting. You can follow me at, appropriately enough, http://twitter.com/plutokiller

Orcus Porcus

No, that’s not going to be the name for the satellite of Orcus. But it was suggested a surprising number of times, and it did make me laugh every time I read it.
When I decided, on a whim, to throw open the naming of the moon of Orcus, I thought I’d get a few suggestions here and there and make a quick decision. More than 1000 suggestions later I’m a bit overwhelmed and thoroughly torn. There were good names, silly names, scholarly names, names of people’s pets and wives and girlfriends (never husbands or boyfriends, though, which is interesting). Names came from came – not surprisingly – from Etruscan mythology, but also Norse, Aztec, Greek, Hindu, and many more. There were references to current media in all forms, there was word play, and there were made up names that simply sounded good (or at least someone thought they sounded good).
After sorting through all of the suggestions, as few interesting names/themes stand out.
First, many attempts were made to fit in to the Etruscan origins of Orcus itself. I will admit that these always had the inside track in my mind. We’ll get back to this in a minute, but first, some of the more popular names and themes that I had not originally anticipated:
Disney-related. With Orcus being described as the anti-Pluto there was some sentiment to pull in Disney mythology instead of Etruscan mythology. I’m not opposed to the general idea of moving beyond ancient mythology, so I thought about these. But the problem with all of these names, I felt, was that there was no connection to Orcus, only to Pluto.
Dungeons and Dragons related. Unbeknownst to me, Orcus has been a major figure in the role-playing game Dungeons & Dragons for the past 30 years. To be fair, though, the phrase “unbeknownst to me” is not exactly true. It really should be “unremembered by me.” My father bought one of the original Dungeons & Dragons sets for my brother and I back in 1976 as a way of keeping his nerdy science fiction loving boys occupied during weekend visits. I will admit to having been an avid player throughout high school. It was a great outlet for a nerdy science fiction loving boy. And though I haven’t thought about it in nearly 30 years, I got sudden senses of nostalgia from all of the D&D related suggestions. I thought of those first few times sitting with my brother and my father (my sister thought we were all crazy) in his apartment trying to figure this stuff out.
But, but, but… Could I really give a name that will stick around for years (hundreds of years? thousands of years? I have no idea) based on a fantasy game that has only been around for thirty years? Would astronomers in 200 years look back on a name like that and think it was a quaint anachronism or just kind of dorky? Maybe. The connections to Orcus are good, even if the mythology is recent.
Tokien related. Many people noted that the word “Orc”, the foot-soldier bad guys from Lord of the Rings, is said to be derived from Orcus (possibly by way of Beowulf) and suggested related names. I should have the same flash backs to nerdy-science-fiction childhood for these suggestions, but I don’t, and I suddenly realized why. Those flashbacks memories seem to keep being overrun by replaced mental images of Elijah Wood and friends running around New Zealand.
There is the same concern about ephemeral popular culture, though these days Orcs are pretty mainstream. But, still, the connection is to the potential origin of the word Orc, as opposed to being to Orcus himself. Somehow, again, that seems not quite right to me.
Silly related. Perhaps the biggest laugh I had when reading these came from someone suggesting “Mindy.” Mindy, of course, was the counterpart to Robin Williams’ Mork. Who was from Ork. The other surprisingly common silly suggestion was “Fiona.” As in, Fiona, bride of Shreck. Shreck, of course, is an Ogre. And then there was – frequently! – “otulP” as in Pluto, backwards. Surprisingly, the more appropriate “norahC’ as in Charon, backwards, rarely showed up.
Un related. People, don’t even start with me. Colbert? Seriously? When people were talking about my discovery of Eris did Stephen Colbert have me on his show? No, he did not. He instead had Neil Tyson. When Pluto was demoted from planet to dwarf planet did Stephen Colbert have me on his show? No, he did not. He instead had Neil Tyson. When Neil Tyson wrote a book about the demotion of Pluto did Stephen Colbert have me on his show? No, he did not. He instead had, well he had Neil Tyson. People, I have this to say: Stephen Colbert is dead to me. And I don’t mean “dead” in a “now-that-he’s-dead-and-in-Hades-hanging-out-with-Orcus-I-can-name-the-satellite-after-him” sort of way, either.
Whale related. Orcus sounds an awful lot like Orcas, as in the “killer whales.” The name Shamu was a shoe-in here, but I liked better the names of the real-life Shamu’s real-life children. Someone even suggested that the name be related to Orcas Island, the largest of the San Juan Island off of the coast of Seattle. It is a well kept secret that part of the appeal of the original name “Orcus” for this Kuiper belt object was that it sounds like the island. My wife Diane lived on Orcus Island through her high school years. We go back to visit as often as we can. The name was a small present to her. She has, of course, thoroughly forgotten about this by now. But I could indeed revive her memory by naming the satellite after something related. One summer while we were visiting and playing our typical game of “let’s pick up a real estate guide and fantasize about houses we can’t afford” I became enamored of this one house that was on a tiny island just off of Orcas Island. You have to go back and forth to Orcas by motorboat to get your groceries, visit your favorite coffee shop, or walk more than 200 yards at a time. I talked about it all the time and how much I would love to have a house on an island like that. Diane became worried that I might actually be serious. I have, in the past, lived in odd places like sailboats and cabins in the woods with no running water. I might have it in me. I think that just to keep Diane a little on her toes, it would be fun to remind her of this time and name the satellite “Crane Island.” But, really, Orcus is not Orcas. And not even Shamu. So I sadly have to pass on this one.
Finally, we get to the more ancient mythology. As I admitted earlier, my heart was always here, though I was willing to consider these other themes.
Overall, the suggestions of and votes for Greek, Roman, and Etruscan mythological characters exceeded all of the other suggestions by a large amount.
The top contenders were Prosperina (a Latinized version of Persephone, wife of Pluto), Vanth (an Etruscan goddess associated with the dead), Phlegyas (a boatman for the dead), and Cerberus (the three headed dog guarding the fates)
At this point, I believe it best to revert to the analysis offered by readers here.
From Sovay:
  • Vanth and Charun are traditionally paired in Etruscan iconography, so her association with Orcus forms a nice parallel to Charon and Pluto; in keeping with the satellite's unclear origins, Vanth's role is not cut-and-dried (she is generally accepted as a psychopomp, possibly a benevolent counterpart to the demonic Charun) and where Orcus and Charon can be traced into other mythologies, Vanth is attested only in Etruscan; and if she accompanies dead souls from the moment of death to the underworld itself, then of course her face is turned always toward Orcus.
From JohnD
  • I suggest "Cerberus", the many-headed guard-dog of Hades. The name has been used elsewhere in the Solar System and the constellations, but not for a semi-planetary body, so I think it would still be allowed. And Cerberus was, in Virgil's words,

    "Orcus' warder, blood-besmeared,
    Growling o'er gory bones half-cleared
    Down in his gloomy den"

    so a classical connection with Orcus.
From Tim:
  • My suggested name is Prosperina. Sources differ, but as far as I can tell, Orcus and Dis Pater (the origin of ‘Dis’, which of course we see as the capital of hell in the Divine Comedy) were synonyms for the same godProsperina was the Roman name for his wife, and you will know her as Persephone, doomed to live for 4 months in hell and for 8 months in heaven because of her consumption of a single pomegranate seed. I like this because I imagine this little moon captured and dragged out on Orcus’ great elliptical orbit, destined to wander far from the plane of the planets for all eternity, a little icy queen of the void. Gosh, I need to go and have a cup of tea to cheer me up now.
From Matthew:
  • Pluto was god of the underworld in Roman mythology, and Charon ferried souls across the river Acheron in early Greek and Roman mythology. Pluto has his equivalent in Orcus, being used as an alternative name for Pluto, and having separate connections to the underworld. Charon, too, has an equivalent in Phlegyas, ferrying souls across the river Styx. Since the Kuiper belt object Orcus can be considered the anti-Pluto and therefore is named due to this relation, it seems fitting to name the first moon of Orcus in a way that fits the connection between Pluto and its first moon, Charon. This, of course, would lead to the name Phlegyas being chosen for “S/1 90482 (2005)”. In addition, Charon, in mythology, seems to be completely connected with the underworld with no indication that he ever existed apart from it. On the other hand Phlegyas does not enter the underworld until Apollo kills him for burning his temple. If Pluto and Charon formed out of a giant collision, as is believed, then Charon's entire lifetime is linked to Pluto. However, if Orcus captured its moon,which may be the case, then it would have existed before its connection with Orcus. This is even further correlation between the connections in mythology of Pluto to Charon and Orcus to Phlegyas and the objects in our solar system. So, to be true to the connection between named objects in the solar system and mythology, as well as to the connection between Pluto and Charon and Orcus and its first moon, I propose the name "Phlegyas" be given to the object “S/1 90482 (2005)”.
And so finally I have to chose, after all of these good names and great discussions. And so. And so. And so…..
Prosperina has a great connection to Orcus, but she is more strongly associated with Pluto than with Orcus. I like the idea of keeping Orcus and Pluto distinct. Cerberus suffers from the same problem.
I am strongly drawn to Matthew’s description of Phlegyas, in particular the strong link to the mystery of the formation of Orcus’s moon. That’s good. Really good. I was almost about to say OK, let’s do it, but I got stuck. Phlegyas is being punished for burning down Apollo’s temple after Apollo killed his daughter. He now wanders Hades reminding people to respect the gods. Are kidding me? If Apollo ever came down and killed my daughter he would get much worse than just his temple being burnt down. And when I went to Hades I would not talk about respecting the gods. Every time I read his story I just get mad. Maybe putting Phlegyas in space releases him from his punishment in Hades.
And finally Vanth. I will tell you this: Vanth got the most votes. It was never my intention that this become an election, but, if it had been, Vanth would be the winner. The appeal to me – and to everyone who voted for Vanth I would guess – is pretty clear. Vanth is one of the few purely Etruscan deities, and a chthonic one at that. She is a psychopomp. I mention these last two facts mainly because I had no idea what they meant until I looked them up (she is an underworld god who conveys dead souls, is what it means). She likes to hang out with Charun, a name which derives, unsurprisingly, from Charon, which makes a nice parallel. And while she’s associated with the underworld, she is a guide rather than an avenger. She awaits the dead and brings them to their new home.
Vanth doesn’t do nearly a good a job of telling the potential story of the formation of the satellite of Orcus, though. So until yesterday I was still unsure. But yesterday while reading about Vanth and reading about Phlegyas, I stumbled across a picture of very nice fresco at the tomb of Anina. Vanth is waiting for the dead, as she is often depicted. It even appears to me that she is silently crying while she waits. Admittedly, I might be misinterpreting, but still, the tear made me think of my sister, waiting for my father – guiding my father – as he took his last breaths.
In a solar system filled with Apollos (asteroid #1862, discovered in 1932) who might kill your daughter, Zeuses (asteroid #5731, discovered in 1988) who might abduct your daughter (or your son, for that matter), Tantaluses (asteroid #2102, discovered in 1975) who might feed you his son, or Erises (the largerst dwarf planet, discovered in 2005) who might start a world war, wouldn’t it be nice to have someone who weeps for the dead? Wouldn’t it be nice to have a guide to light the way?
So it will be Vanth.
The citation submitted to the IAU has to be short and can only hint at the richness of everything that has gone on here. It will read:
S/1 (90482) (2005) Vanth

Discovered 13 Nov 2005 by M.E. Brown and T.-A Suer.

Vanth is a daimon in Etruscan mythology who guides the dead to the underworld. She often appears on tomb paintings and sarcophagi where she is depicted with wings and a torch, and she is frequently shown in the presence of Charun, a guard of the underworld. Name suggested by Sonya Taaffe.
Thanks to everyone for participating. Having gone through all of this, I realize that naming a moon was perhaps a bit too constraining, as the theme was already in place. Next time perhaps we will try to find a name for one of the many many other objects out there that are deserving and for which the field is wide open. As always, stay tuned.

S/1 90482 (2005) needs your help

“S/1 90482 (2005)” is really not much a name as a license plate number. As does a license plate number, it tells you pretty much everything you need to know to identify the object in question. “S” is for satellite. “/1” means it is the first discovered. The “2005” at the end tells the date of discover, and the “90482” tells whose satellite it is, but only by yet another number. This number refers to the 90482nd minor planet (in the old terminology; no one quite knows what the new terminology is, but the numbers keep coming) to be officially recorded. That object is more commonly referred to as the large Kuiper belt object Orcus. We don’t ever call the moon of Orcus by its official name of S/1 90482 (2005). Instead, around here, it is referred to mostly as “the moon of Orcus.”

It’s time to change that.

Not all of the Kuiper belt objects known and number have names, and, as I have written here earlier, I think most don’ t need them. It is OK to consign them to semi-anonymous license plate numbers if they are never really going to be thought about as more than one of the crowd. But a few special objects get studied and talked about and written about enough that need not so much just names, but also personalities. Orcus was one of those objects. Its personality was quite apparent from the beginning.

We discovered Orcus in early 2004. At the time it was the 4th largest known Kuiper belt object, though by now it has dropped to something like 8th. The most interesting thing about Orcus to me was that it appeared to be the anti-Pluto.

Pluto has what was originally thought to be a peculiar orbit. It circles the sun precisely two times for every three times that Neptune goes around the sun. Though it took astronomers a long time to realize it, this peculiarity is not a coincidence. Neptune’s gravity so dominates the region of space where Pluto is that Neptune has herded Pluto into this very special orbit. Pluto is not the only one that Neptune is pushing around. We now know of hundreds of similar objects in the Kuiper belt, including, now, Orcus.

Pluto’s orbit has a few other interesting features to it. It is so elongated that, for a brief time during its revolution about the sun, it actually comes close to the sun than does Neptune. So does Orcus. When Pluto comes close to the sun, though, it is never actually close to Neptune, partially because at that point in its orbit it is high above the disk of the planets, hitting the most extreme spot of its tilted orbit. Just like Orcus.

In fact, if you look at the orbits of Pluto and Orcus (and I encourage you to do it if you never have; check out the extremely cool orbit plotter at JPL but you'll have to zoom out to find Orcus), you will see that they are nearly identical except for 2 things. Their elongated orbits point in nearly opposite directions, and, right now, Pluto is nearly as close as it ever comes to the sun while Orcus is nearly as far away as it ever comes. In fact, because Pluto and Orcus are forced by Neptune to have precisely the same orbital period, they will always stay in opposite phases of their orbits.

Orcus is the anti-Pluto.

Several years ago, when searching for a name for what was then known only as 2004 DW, we decided to concentrate on the anti-Pluto aspect of the object’s personality, and we came up with Orcus. In the version of the Orcus myth that I like to tell, Orcus was, essentially, the early Etruscan grim reaper, collecting the dead and bringing them to the underworld where another god – Pluto – ruled. As the Etruscan mythology was incorporated into Roman mythology and blended with Greek mythology, Orcus lost his separate identity and Pluto became the master of all of the functions of the dead. Orcus became in some ways simply an alternate name for Pluto, but it also remained a slightly more evil and punishing incarnation of Pluto. In that incarnation, the Latin word Orcus was the origin of words such as ogre and orc.

In my new mythological/astronomical view, Pluto the Kuiper belt object is now named after that earlier version of Pluto, before the Romans came along and swept everything together. And Orcus is his counterpart, destined to eventually be pushed aside by the rising Pluto. Orcus seemed a very appropriate name for this new object in the Kuiper belt.

About a year later, while looking carefully at Orcus with the Hubble Space Telescope, we realized that it had a moon. In the past year we have been studying the moon of Orcus intensely and are in the final stages of writing a scientific paper on all of the interesting things about this moon. Which means it is time to stop calling it “this moon” and give it a proper name. But what?

Here’s where you come in. Send me suggestions! I’ll submit the best suggestion to the International Astronomical Union on Sunday, April 5th (about 2 weeks from now) with your name as part of the official citation (if you want it to be).

If you make a suggestion I would like to know not just what the suggestion is, but why you think its appropriate. As you can tell by now, this is the part that matters to me!

To help you out, let me tell you some of the other interesting things about the satellite. It has about a ten day orbit around Orcus, in a tight precise circle. We suspect – though can’t yet prove – that Orcus and its satellite have their same faces locked towards each other constantly, like an orbiting dumbbell. Only one other Kuiper belt object and satellite are known to do this. Who? Pluto and Charon, of course.

The origin of the satellite of Orcus is confusing. Pluto and Charon are thought to have formed in a giant collision. Haumea clearly had a shattering blow to disperse moons and other family members. But small Kuiper belt objects are thought to acquired moons by simple capture.

Orcus is right in the middle. Was the satellite from a collision or a capture? We had hoped to answer this question by observations from the Hubble Space Telescope. If the satellite had looked just like other known collisional satellite, we would have been pretty convinced. It doesn’t. Unfortunately that tells us less. We can’t rule out either. We have some ideas of new Hubble Space Telescope observations to try to tell the difference. For now, though, we’re just confused.

While the scientific paper will have more details and calculations, that will be the gist of it, and those properties are all you get to know to try to discern the personality of the moon of Orcus and to try to pull out the right name.

You can send suggestions as comments to these pages (www.mikebrowns planets.com in case you are reading this elsewhere) or simply email me ( ), but please put “Orcus” in the subject line so I don’t mistake you for a potentially business partner from Nigeria.

Good luck. S/1 90482 (2005) is counting on you.


On December 28th, 2004, I discovered a Kuiper belt object brighter than anything anyone had ever seen before. Being only a few days after Christmas, I naturally nicknamed it Santa.
The discovery was bittersweet. I had made a bet with a friend 5 years earlier that someone – anyone! – would discover a new planet by January 1st, 2005. The deadline was in 3 days, but I knew that Santa didn’t count. We didn’t know exactly how to define “planet” back then, but we decided that something of a particular brightness would count. Santa was bright , but not quite bright enough. Three days later I had still not found anything bright enough to count, and I lost the bet.
But, still: Santa! How would I have known back in 2004 that Santa would be the single most interesting object ever discovered in the Kuiper belt? It has a moon – wait, no, two moons! It is oblong, sort of like a football (American style) that has been deflated and stepped on. And it rotates end over end every 4 hours, significantly faster than anything else large known anywhere in the solar system.
Large? Well, at least sort of large. The long axis is about the same size as Pluto or Eris or Makemake. Back when I thought that maybe the IAU was going to vote that anything the size of Pluto or larger was a planet I was going to argue that Santa was indeed a planet – as long as you looked at it at exactly the right angle (luckily, the IAU was much more sensible, so I did not have to make such a crazy argument).
Stranger still, Santa has the density of a rock. We think that most things out in the Kuiper belt are about equal portions of rock and of ice, but, apparently, this does not apply to not Santa. It’s only rock. Except that even that is not true. When we finally got a chance to look closely at its surface with the Keck telescope we realized that the surface is nothing but ice. Santa must have a structure like an M&M, except that instead of a thin layer of sugar surrounding chocolate, the thin outer shell is ice and the interior is rock. Don’t bite.
These characteristics already make Santa the strangest object in the Kuiper belt. Several years ago we came up with what thought was a good explanation. What if, eons ago, Santa was an even larger Kuiper belt object and it got smacked – in a glancing blow – by another Kuiper belt object? That would explain the fast spin. And the fast spin would be enough to explain the oblong shape; anything spinning that fast would be pulled into such a big stretch.
What’s more, the initially large Santa could have had a rocky interior and icy exterior, much like the Earth has an iron interior and a rocky interior. When the huge impact occurred, it could have cracked that outer icy mantle and ejected all of that ice into space. The two moons that circle Santa are pieces of that icy mantle.
This explanation was, we thought, pretty good. And then it got really good.
While looking across the Kuiper belt at many different objects, we realized that a small number of objects in the Kuiper belt look like tiny little chunks of ice. How strange. Even stranger, though, was that all of these chunks of ice were, relatively speaking, next-door neighbors of Santa. We had found the other chunks that had been removed from the mantle of Santa. The story was complete.
After we discovered Santa, we worked hard to get the first scientific paper ready to announce the discovery. In science there is always a tension between doing the careful work to make a complete announcement and doing an instant but incomplete announcement in order to make sure you don’t get scooped. We were as worried as anyone about being scooped, but we resisted the temptation for instant announcement. We felt that the science was too important.
On July 7th 2005, as I was putting the finishing touches on the scientific paper, in hopes of submitting it the next day, I had a minor delay. My daughter was born. I had somehow convinced myself that there was no way that she would be born for another week. I was certain that I had more time. But I had no more time, no more time at all. I forgot about Santa and the rest of the Kuiper belt and turned my obsession from it to her. The announcement about Santa would have to wait, I was too busy sending out announcements about Lilah, instead. What difference would a few months make, really?
The announcement did indeed wait, but only for 21 more days. On a late Thursday night, between changing diapers and filling bottles and descending ever more into sleep deprivation, I checked my email and saw the announcement of the discover of Santa myself. A previously unheard-of Spanish team had just discovered Santa a few days earlier. And they called it the tenth planet.
No no no no no no no no! I was horrified. My discovery had just been scooped by a group who decided not to wait to learn more. They didn’t know any of the information about Santa that we did, in particular that it has a satellite and from the orbit of the satellite you could tell that it was only 1/3 the size of Pluto, and that it was definitely not the tenth planet. Worse, a few months earlier, we had actually discovered something that was bigger than Pluto. This was going to cause nothing but confusion.
That night, on no sleep but much caffeine, I stayed up to finish the paper about Santa that I had put aside three weeks earlier. We would not get credit for discovery, which was painful enough, but at least we would quickly set the record straight about its size and importance. After I sent the paper off, I sent a quick email to congratulate the Spanish team on their discovery and I filled them in on everything that we knew so that they could answer questions from the press correctly. Finally I nodded off to sleep.
I woke to a nightmare. In the intervening hours it appeared that someone had used the knowledge that we had been tracking Santa to start looking into what else we had been doing. Someone had traced where we had been pointing our telescopes for the past months. We had been pointing them at the object that would one day be called Eris – the object bigger than Pluto, the real tenth planet! That morning, the astronomical coordinates of Eris were posted to a public web page with discussions about what might be there that we had been watching. It was clear to me that as soon as the sun went down that night, anyone with a moderately large amateur telescope could point up in the sky at those coordinates and, the next day, claim they had discovered the 10th planet.
After breakfast, I apologized to my wife; I would have to go in to work today for the first time in three weeks.
I called my wife later in the day to apologize again. I was going to have an international press conference that afternoon and would she mind bringing me some nicer clothes? And a razor, perhaps? And more coffee. Definitely more coffee. That evening, the world learned that there were 10 planets.
After more than three years, Santa received a formal name today. Santa is now, and forever, officially Haumea. From the official citation issued by the International Astronomical Union:
Haumea is the goddess of childbirth and fertility in Hawaiian mythology. Her many children sprang from different parts of her body. She takes many different forms and has experienced many different rebirths. As the goddess of the earth, she represents the element of stone.
The name was chosen by David Rabinowitz of Yale University, one of the co-discoverers of Santa (along with me and Chad Trujillo of Gemini Observatory in Hawaii). He chose the name because Haumea is closely associated with stone, and Santa (as we knew it at the time) appeared to be made of nothing but rock.
But the name is even better than that. Just like the Kuiper belt object Haumea is the central object in a cloud of Kuiper belt objects that are the pieces of it, the goddess Haumea is the mother of many other deities in Hawaiian mythology who are pieces pulled off of her body.
Two of these pieces are Hi’iaka, the patron goddess of the big island of Hawaii, who was born from the mouth of Haumea, and Namaka, a water spirit, who was born from the body of Haumea. These names were chosen for the brighter outer moon and the fainter inner moon, respectively.
Haumea I, Hi'iaka, discovered 2005 Jan 26 by M.E. Brown, A.H. Bouchez, and the Keck Observatory Adaptive Optics team

Hi'iaka was born from the mouth of Haumea and carried by her sister Pele in egg form from their distant home to Hawaii. She danced the first Hula on the shores of Puna and is the patron goddess of the island of Hawaii and of hula dancers.

Haumea II, Namaka, discovered 2005 Nov 7 by M.E. Brown, A.H. Bouchez, and the Keck Observatory Adaptive Optics teams

Namaka is a water spirit in Hawaiian mythology. She was born from the body of Haumea and is the sister of Pele. When Pele sends her burning lava into the sea, Namaka cools the lava to become new land.
But wait! Shouldn’t the official discoverer get to name the object? What of the Spanish team?
Yes. The discoverer should.
Several weeks after the Spanish team announced the discovery of Santa which precipitated the announcement of the object that would eventually be named Eris, which precipitated the entire discussion of dwarf planets, it became clear that the Spanish team had not been forthcoming. They themselves had been the first to access the web sites which told where our telescopes looked. And they did this access two days before they claimed discover (you can see a detailed timeline reconstructed from the web logs here)
Did they use this information to claim the discovery for themselves?
As a scientist, my job is to examine the evidence and come up with the most plausible story. Here are some possibilities. It is impossible to disprove this story, claimed by the Spanish team: while looking through two-year-old data, they discovered Santa legitimately, and then, only hours later, accessed information about where our telescopes had been looking and were shocked (shocked!) to realize that the object they had just found was the same object that we had been tracking for months. Wanting to establish priority, they quickly announced, knowing essentially nothing about the object.
Though this story cannot be disproved, it does not have much of an air of plausibility about it. Data that were two years old happened to get analyzed just hours before – whoops! – the team found out that someone else had found the same thing? Hmmmmm. Perhaps most damning, you would think that perhaps the Spanish team would be willing to admit this early on. Instead they appeared to attempt to hide the fact that they ever knew anything about our telescope pointings.
Let’s try a more plausible explanation: the Spanish team found our telescope pointings, used that information to infer the existence of Santa, and assumed that no one would ever know they had not found it legitimately.
No way to prove it, but the later hypothesis certainly sounds more plausible. To be fair, though, I don’t think there is any way to ever know the full extent of the truth, except on the off chance that someone on the Spanish team eventually spills the beans about what really happened. I keep waiting, but I don’t hold my breath.
But wait, there’s more to ask! If the telescope pointings were – even if inadvertently – on a publicly accessible web site, was it wrong to look at them? The obvious answer is that there is nothing wrong with looking at information on any publicly accessible web site, just as there is nothing wrong with looking at books in a library. But the standards of scientific ethics are also clear: any information used from another source must be acknowledged and cited. One is not allowed to go to a library, find out about a discovery in a book, and then claim that discovery as your own with no mention of having read it in a book. One is not even allowed to first make a discovery and then go to the library and realize that someone else independently made the same discovery and then not acknowledge what you learned in the library. Such actions would be considered scientifically dishonesty.
In the end, while we are likely to never know exactly what happened, it appears clear that the Spanish team was either dishonest or fraudulent. They have claimed the facts that merely make them dishonest. If I had to bet, though, I would bet for the later.
Officially, the naming of Haumea does nothing to put to rest this three-year-old controversy. The committee that voted to accept the name has said that, while they will take the name proposed by our team rather than the name proposed by the Spanish team, they are not favoring one claim over the other. They will let posterity decide.
OK, posterity, have at it. If I am no longer around to hear the news on the decision, that’s ok, you can tell my daughter Lilah instead. She will have been waiting, nearly precisely, her entire life.


Several readers pointed out that the correct Polynesian pronunciation of Make-make is not Maki-maki, as I suggested, but rather MAH-kay MAH-kay (where the capitals show accent). These readers are, of course, correct.

I find this mistake distressing as I spend so much time in Hawaii at telescopes that I think myself a proper Hawaiian-pronunciater. I can glance up at a street sign and read ten syllables in appropriate Hawaiian while my wife is still sounding through the first letters.

Hawaiian is easy. The "e" is always pronounced "ay". I get a demonstration of this every time I visit the summit of Mauna Kea to use the Keck telescope. Or when I just stay in the town of Waimea, where the Keck headquarters are. Or make sacrifices to Pele before observing (which, well, I admit to sometimes doing; she allegedly likes hard alcohol these days rather than virgins, being in shorter suppy).

But the first time I saw the name Make-make the wrong pronunciation just flowed out so easily (influenced, no doubt, by the Wiki-wiki buses at the Honolulu airport [wiki-wiki, meaning something like "quick quick." The buses are not particulatly wiki-wike, though]) that I never paused to get it right.

Sorry Make-make. And thanks to those who set me straight.

Plutoid fever

Almost two years ago, during the same contentious meeting in which Pluto was demoted from a full-fledged planet to a “dwarf planet,” a few other votes were taken, but mostly forgotten. One of the forgotten votes that was actually approved was that Pluto was to be declared the” prototype of a new class of objects”. OK. Done. What exactly that means is a bit hard to say. As far as I could tell it was an attempt to be nice to Pluto after the indignity of its demotion. Who would vote “no” to that?
The next vote that was taken was about what to call this new class of objects. The proposal, if I remember correctly, was to call them “Plutonian objects.” The proposal was voted down by a very small margin. Why, again? Hard to say. People were in funny moods.
The class of objects, then, remained unnamed, with a promise – a threat – that a committee would come up with something and there would then be no vote.
The committee has spoken! After the close vote on “Plutonian objects”, the committee deliberated for almost two years and settled on “Plutoids” and now it is settled. A “Plutoid” is a dwarf planet (meaning it must be large enough to be round) that is beyond Neptune.
But wait! There’s more! The committee did more than promised! They added one more twist to the rule. While originally all dwarf planets beyond Neptune were to be part of this new category, the committee decided to restrict the definition to the brightest of the dwarf planets. For now the only ones that count are Pluto itself, as well as three of my babies: Eris, 2005 FY9, and 2003 EL61.
I have been asked: will there be controversy? Will there be bickering? Will people fight and contend?
I suspect the answer is, in fact, that there will mostly be nothing.
The class of objects was supposed to get a name, now it has a name. The name seems pretty non-controversial, if also a bit clunky.
The one thing that almost no one will even notice is the part that I find the most odd, though, which is the restriction that the object be a particular brightness. Not a particular size: a particular brightness.
That makes for some funny situations. If you take Pluto and cover it with dirt it would no longer be a Plutoid. Or take something much smaller and cover it was snow instead of rocks and it might be a Plutoid. Or, may favorite example, if you take Eris, which is currently the intrinsically brightest object, bring it closer to the sun (where it will be in 290 years), melt some of the ice on the surface, and exposure some of the darker substrate, it might just get dark enough to no longer be a Plutoid. Now you see it; now you don’t.
[a clarification, from Daniel Fischer]
But, OK, it’s a definition. And I can at least understand the committee’s feeling that they wanted to put a concrete brightness limit instead of a harder to determine roundness limit.
What does anyone else think?
There is still a small but extremely vocal group of astronomers who remain incensed about Pluto’s demotion. They will use this as a soapbox to repeat their initial complaints about Pluto.
Other astronomers are likely to yawn. Plutoids? Sure, why not. Most astronomers have moved well beyond the Pluto-debate and the semantics associated with it. If Pluto is happy being a Plutoid then it is probably OK with the rest of us.