Comets: Facts about the 'dirty snowballs' of space

NASA has a Ballistic air gun to Hurl Rocks at Space Suits to Test Their Micrometeorite Protection

Gigantic cavity in space sheds new light on how stars form

Astronomers analyzing 3D maps of the shapes and sizes of nearby molecular clouds have discovered a gigantic cavity in space. The sphere-shaped void pans about 150 parsecs—nearly 500 light years. Researchers believe the cavity was formed by ancient supernovae that went off some 10 million years ago.