Aerogel in Hand Produced by:   NASA/JPL Copyright:  NASA Copyright Free Policy Date Released:  13 June 2001

• Stardust Spacecraft

Aerogel Quick Facts

• It is 99.8% Air
• Provides 39 times more insulating than the best fiberglass insulation
• Is 1,000 times less dense than glass
• Was used on the Mars Pathfinder rover

Aerogel is a silicon-based solid with a porous, sponge-like structure in which 99.8 percent of the volume is empty space. By comparison, aerogel is 1,000 times less dense than glass, which is another silicon-based solid. When a particle hits the aerogel, it buries itself in the material, creating a carrot-shaped track up to 200 times its own length. This slows it down and brings the sample to a relatively gradual stop. Since aerogel is mostly transparent - with a distinctive smoky blue cast - scientists will use these tracks to find the tiny particles.