This picture shows what an artist thinks Stardust might look like flying by Comet Wild 2 in January 2004. Click on image for full size (54K JPEG) Image courtesy NASA/JPL.

Stardust is the name of a space mission that studied a comet. NASA's Stardust spacecraft flew past a comet named Wild 2 in January 2004. During its flyby Stardust collected some dust particles from the comet. The spacecraft brought those dust particles back to Earth so scientists can study them.

Scientists are learning what a comet is made of by studying the dust that Stardust collected. Some comets haven't changed very much since they formed in the early days of our Solar System. Knowing what comets are made of may help us understand what our Solar System was like soon after it was "born".

The Stardust spacecraft used a strange material called aerogel to capture dust particles from the comet. The dust was moving very fast - about 21,960 kilometers (13,650 miles) per hour - as it zoomed by Stardust. Aerogel is so light and fluffy that it was able to stop and capture dust grains without destroying them. A capsule from the spacecraft carrying the dust grains landed back on Earth in January 2006. Stardust also shot the best pictures ever of the nucleus of a comet during its flyby.

Right now scientists are studying the dust that Stardust brought back. They have already had a surprise. Comets are large balls of ice. But the samples Stardust brought back included some minerals that form at high temperatures! These minerals normally form near the Sun (or some other star). Scientists don't know how the minerals got out to the frozen edge of the Solar System where comets are.