Using a telescope on the roof of the Hall of Science, Zach Schierl ’12 captured several images of an asteroid which, on Nov. 8, made the closest approach to Earth of any asteroid known. At 200,000 miles away, passing just inside the orbit of the Moon, the asteroid is also the biggest to come so close in 35 years.

“It was moving extremely rapidly relative to the Earth and moved during the 25-second exposure while the telescope tracked the stars,” said Nathaniel Paust ’98, Whitman assistant professor of astronomy. The asteroid appears as a streak in Schierl’s photo due to this high speed.

Astronomers first detected the asteroid, named Asteroid 2005 YU55, six years ago with the Spacewatch Telescope at the University of Arizona’s Steward Observatory. It measures a quarter-mile across, about the size of an aircraft carrier.

Paust explained that while the asteroid, too faint to see with the naked eye, is not likely to make impact with Earth in the next 100 years, the close approach marked an historic moment. If it were to strike Earth, the resulting explosion would be several thousand times larger than Hiroshima, he said.

Schierl, an astronomy-geology combined major from Flagstaff, Ariz., is working with Paust on a project aimed at enhancing the ability of Whitman students to conduct astronomical research on campus. Whitman is the only school in the Pacific Northwest other than the University of Washington with an independent astronomy department, and maintains about 10 telescopes on the roof of the science building as well as two research-focused telescopes and an observatory in the wheat fields north of campus. Schierl used a 14-inch Calestron telescope, the biggest on campus, to capture the images.