A Solid That's Light as Air
Found on Wired on Wednesday, 22 February 2006
If you wanted to catch a few particles of comet dust speeding through the vacuum of space at 6 kilometers per second -- without damaging or destroying those particles -- how would you do it?
Faced with exactly this problem, scientists at the Jet Propulsion Laboratory focused on aerogel -- an extremely lightweight, porous material that is chemically identical to glass, but weighs only a little more than air.
Aerogel is the lightest solid known to science. It's also one of the most insulating materials on Earth, the most porous, and it's nearly transparent. Those last two properties made it an ideal choice for catching flecks of comet and interstellar dust on the recently-returned Stardust mission launched by NASA and JPL.
While it still is a neat substance, this is pretty old news. It was mentioned already 2 years ago in Science Daily; the NASA also covered the "solid smoke".