Planetary scientist Dan Durda returned to the show to give an update on near Earth asteroids. Of particular interest is asteroid 2004 MN4, which is going to have a close-flyby with Earth in 2029. It'll be closer to Earth than our own satellites and be naked-eye visible with particularly good views in Europe, he noted. The object, which is estimated to be about 320 meters across (about 3 football fields), will be able to be observed moving across the sky, he added.

Though the asteroid won't hit us in 2029, there's some danger the object could collide with Earth during its next pass in 2036, he pointed out. As a member of the B612 Foundation, Durda is working on methods to safely deflect future asteroids that come our way. The goal, he stated, is move the asteroids in a slow, controlled manner, so that they don't come back to hit us later.

More asteroids such as 2004 MN4 are likely headed our way, and there is currently an ongoing project through 2008 to locate such objects, he said. NASA's Near Earth Object Program allows people to track potentially hazardous asteroids as they are discovered. Durda also spoke about planetary discoveries and potential life in the universe.