Even though Deep Impact smashed into Comet Tempel 1 several months ago, scientists are still analyzing the data gathered before and after the collision. Very few close up pictures of comets have ever been taken, so the data gathered by Tempel 1 is very valuable, and sometimes surprising. The nucleus of Temple 1 has layers that show in topographic relief, ranging from smooth surfaces to impact craters. It's also extremely porous, which allows the surface to heat up and cool down almost instantly when hit by sunlight.