A team of scientists discovered evidence of caves on the Moon's surface using data from NASA’s LRO (Lunar Reconnaissance Orbiter). Data collected by LRO’s Mini-RF (Miniature Radio-Frequency) instrument in 2010 found evidence that a cave extends over 200 feet from the base of a pit, which is located 230 miles northeast where the Apollo 11 mission landed on July 20, 1969. The full extent of the cave, located near the Sea of Tranquility, is unknown but is expected to stretch for miles, according to NASA. Like 'lava tubes' on Earth, scientists suspect that the lunar caves were formed when molten lava flowed beneath a field of cooled lava, or a crust formed over a river of lava, leaving a long, hollow tunnel. If the ceiling of a solidified lava tube collapses, it opens a pit, like a skylight, that can lead into the rest of the cave-like tube. Scientists have suspected for decades that there are subsurface caves on the Moon. Pits that may lead to caves were suggested in images from NASA’s lunar orbiters that mapped the Moon’s surface before NASA’s Apollo human landings. A pit was then confirmed in 2009 from images taken by JAXA’s (Japan Aerospace Exploration Agency) Kaguya orbiter, and many have since been found across the Moon through images and thermal measurements of the surface taken by LRO.
