Bad Astronomy

The return of Stardust

Update 3 (last for the night; I’m tired!): The capsule landed! Strong winds blew it a bit off course, but at 2:54 local time the capsule was spotted by helicopter.

I was out with Mrs. Bad Astronomer and the Littlest Astronomer, but we missed it. I am guessing it was just too faint to see, but it’s possible we simply missed it since it was moving quickly. I can’t really be sure. Oh well! Sunday, when I have more info, I’ll post about it.

Update 2: Stardust has been spotted! Bill Keel, a professional astronomer and poster on the Bad Astronomy/Universe Today bulletin board, reports that he and his students have spotted the spacecraft when it was still 160,000 km away. He has an image posted on his website.

Update 1: Emily Lakdawalla has posted an updated timeline on her Planetary Spociety Blog.

On the evening/morning of January 14/15, the Stardust probe returns to Earth. Wanna take a look?

OK, first, what is Stardust? It’s a NASA mission launched in 1999 to get up close and personal with a comet named Wild 2 (named after its Swiss discoverer, it’s pronounced “vilt”; listen for newscasters tonight mispronouncing it as “wild”). Stardust passed within 240 kilometers of the comet’s nucleus in early 2004 and took this way cool image:

When it’s near the Sun, the comet nucleus is surrounded by a cloud of gas and dust that is emitted by the nucleus. When Stardust passed through the cloud, it extended a tennis-racket-shaped collector which snared these comet bits. Instead of a net, to snare the particles the collector used a substance called aerogel, which is extremely lightweight, resistant to heat, and able to decelerate the particles without destroying them (it’s like a super-styrofoam). Scientists want to be able to study these particles in their labs (sending a complete lab on a spaceship would be a tad pricey), so the Stardust spacecraft will eject a capsule containing the particle-laden aerogel, which will then fall to Earth.

The comet sample capsule will be ejected from the main spacecraft at 05:57 a.m. Universal time Sunday morning (9:57 p.m. Saturday night Pacific time). Four hours later, at 09:56 a.m. UT (01:56 a.m. Pacific time) it will re-enter the Earth’s atmosphere at a whopping 46,400 km/hr (28,800 mph), making it the fastest manmade object to ever do so.

And you might get to see it! If you live in the western US or the extreme southwest part of Canada (and it’s not raining, dagnappit!) you may very well get your chance. The capsule will re-enter over the Pacific ocean off the Oregon/California coast, heading east and slightly south for a touchdown in northern Utah.

If you want to take a look, you’ll have to know where to look, and that depends on your location. The Stardust mission folks have provided a handy-dandy map to help you out:

This map tells you how high off the horizon Stardust will appear for various locations. From where I am, a little north of San Francisco, it will be roughly 15 degrees above the horizon (somewhat more than the size of your fist held at arm’s length). I may try to see it tonight, but it’ll probably be raining here. Sigh.

If you are in the right area, viewing it shouldn’t be too hard (a very detailed description is online at the NASA website). Start early, just to make sure! Start looking around 01:50 a.m. local time (and make sure you have an accurate clock!). If you are south of the re-entry line, look north. If you are north, look south. Around 1:55 or so you might be able to spot it as a faint star moving east. Within a minute or two it’ll get much brighter– but remember, the farther away you are from it, the fainter it will be. According to this graph it will get as bright as magnitude -6 – 5 times brighter than Venus! – viewed from 100 kilometers away, if you are downrange (east) of it looking straight at it. The front part of the capsule is what will be bright, so from the side it will look fainter. I am 250 km away, and will see it from the side, so I am not sure how bright it’ll be to me, but I hope to catch it with binoculars. I don’t think it’ll leave a vapor trail like a meteor would, but it might. After re-entry, it will fall the rest of the way to Earth, landing in the northern Utah desert where it will be picked up by helicopter.

For a lot more information on how to view the re-entry, get yourself over to the Stardust viewing page created by the Stardust re-entry team. It has timetables, maps, and all sorts of other things to help you see this remarkable piece of history as it falls from the sky. There is also a page with cool facts about the mission, too.

As for me, I plan on climbing up on the roof of my house (carefully, oh man, since it’ll be wet, and it’ll be late, and I’m still recovering from the AAS meeting) with binoculars, my tripod, and my camera. If it’s clear, and I get pictures, you can be sure I’ll post them as soon as I can.’