He is a Senior Editor at Discover magazine, where he assigns and edits the news section and edits feature articles on astronomy, physics, and paleontology.

He is also an adjunct professor of science journalism at NYU's Science and Environmental Reporting Program. Previously he directed the launch and operation of Discover's web site, Discover.com.

Before joining Discover he spent eight years on the Board of Editors at Scientific American, and also worked at Physics Today and at NASA's Goddard Space Flight Center, where he assisted in the testing of gamma-ray telescopes.

His first book, God in the Equation (an exploration of the spiritual impulse in cosmology), was issued in paperback last summer by the Free Press. Powell lives in Brooklyn, where it is depressingly easy to count the number of stars in the sky.