Dr. David Morrison is senior scientist at the NASA Astrobiology Institute, and a founder of the multidisciplinary field of astrobiology. He is an expert on the risk of asteroid impacts and potential ways to mitigate that risk. Scientists are currently studying a 300-meter diameter asteroid, called Apophis.

Apophis will pass within a few thousand kilometers of Earth on April 13, 2029, and could theoretically, depending on its trajectory, collide with the Earth on April 13, 2036. Morrison explains that Apophis is not an imminent threat, and that we are more at risk today from the objects that have not been discovered by scientists.

Read the "Who's Who at NASA" interview with David Morrison on page 10 of the June issue of NASA Tech Briefs, or click here .