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.



Summer project: Build a radio telescope at home

When we moved into our house more than 7 years ago now the old owners left their Dish Network satellite TV dish attached to the roof. A few months later we got a sternly worded letter from the Disk Network demanding that we send them the dish back. With my detailed knowledge of the intricacies of the American legal system my obvious response was: come and get it. Which would have been fine with me. But, actually, that was not even my response, my response was to throw the letter in the trash while thinking in my head "come and get it."

Seven year later the dish was still on the side of the house. Luckily it is on the side that I never really see, so I didn't worry about it, but every now and then I thought to myself: "I should at least go up and take down that eyesore." But I never did. Until now.

I occurred to me a while ago that a parabolic dish like that would make a fine radio telescope (OK, it will end up a microwave telescope, but we'll get into the details later).

I'm not a radio astronomer or an electrical engineer or a Ham radio guy or any of that stuff, so I really had no idea what I was talking about, but it seemed a fun project for Lilah and I to play around with for the summer and for both of us to learn a little bit about microwaves. The caveat, though, is that my electronic explanations might not be exactly right. And I might break things.

We started last week. Step 1: remove the dish from the roof and see what was there. I had to snip the coax cables that went into the house and then undo five big screws and then everything just came unceremoniously down. The main issue was figuring out how to hold the wrench, dish, and ladder at the same time without falling. Luckily I survived this crucial part. Lilah stayed far enough away to avoid getting a dish on her head but to be able to both take pictures of me and make fun of me each time I dropped something and had to go pick it up.