Rare Hole In the Moon Photographed
Impact craters are visible everywhere on the Moon, but pits are rare. This pit in Mare Ingenii (located at -35.95°N, 166.06°E) is about 427 feet (130 meters) in diameter. <a href=http://www.space.com/scienceastronomy/rare-moon-hole-photographed-100624.html>Full Story</a>.
Credit: NASA/GSFC/Arizona State University

New photos of the moon have revealed the most detailed views yet of a rare hole in the lunar surface — a pit large enough to swallow an entire football field whole.

High-resolution cameras aboard the Japanese Kaguya spacecraft first spotted the irregularly shaped chasm, located in Mare Ingenii on the moon's southern hemisphere. Now, NASA's Lunar Reconnaissance Orbiter has taken a new, up-close photo of the moon pit from lunar orbit.

"Only three have been discovered thus far, so I believe it is safe to state that skylights (pits) are rare at the 100-meter scale," Mark Robinson, principal investigator for the Lunar Reconnaissance Orbiter Camera (LROC) at Arizona State University, told SPACE.com in an e-mail.

Mare Ingenii, also called the "sea of cleverness," is best known for its prominent lunar swirls, which are highly reflective surface features that are associated with magnetic anomalies. The new images of the region from LROC show a giant pit measuring about 427 feet (130 meters) in diameter.?

The boulders and debris resting on the floor of the cavity are partially illuminated and likely originated at the surface, falling through the pit opening during its collapse. The hole is thought to be the result of a partially collapsed lava tube.

A similar moon pit, which was believed to be a skylight into a lava tube, was previously discovered by the Kaguya mission in the Marius Hills region of the moon. The new pit in Mare Ingenii, however, lacks the numerous volcanic features that were found in the Marius Hills region.

"The existence of lava tubes and thus skylights had long been postulated," Robinson said. "However it is a surprise to me how large and beautifully preserved are the three that we have seen thus far."

Closer examination of Mare Ingenii could help scientists understand the differences between the two areas of the lunar surface, and such discoveries could also spur on further exploration of the moon, said Robinson.

"Imagine how fantastic it would be to land in one of these skylights and explore underground on the moon!" he said.