What's the Latest Development?

Scientists have found a large variety of fully-formed nucleobases–the essential building blocks of DNA–in meteorites, reports Pete Spotts. The discovery has been interpreted by some experts as suggesting an extraterrestrial origin for some of the chemicals deemed necessary for organic life.

What's the Big Idea?

Scientists have concluded that some of these key components of DNA may have been delivered to Earth ready-made by chemical reactions that took place on asteroids or comets as the solar system  evolved. "And if it can happen in our solar system, (NASA's Michael) Callahan suggests, under the right conditions these building blocks can find their way to hospitable planets elsewhere."