What’s as light as smoke but strong as a brick?
The answer: aerogel.
Aerogel is the lightest solid on earth. It starts out as a kind of chemical Jello®. Then the gel is dried in a powerful pressure cooker and emerges as a very lightweight, dry, sponge- like material that looks like frozen smoke. Aerogel is also ninety-nine-point-eight percent air.
It’s incredibly light–one thousand times less dense than glass. But it’s also really strong and an excellent insulator. Scientists are using it to try to capture dust particles from the tail of a comet. When the particles slam into an aerogel panel aboard a space probe, they’ll bury themselves inside and leave visible trails. Since aerogel is mostly air, it won’t damage the particles.