Second Glance

Impact craters and tall ridges scar the face of Comet Tempel-1 in this image from NASA's Stardust spacecraft, which flew past the comet on the night of February 14. Another spacecraft, Deep Impact, observed the comet in 2005, so this was a second look at the icy comet. Planetary scientists will examine the images to determine how the comet has changed between encounters. [NASA/JPL/Cornell]