The Atlanta Journal-Constitution
Moon tunnel could be perfect place for colony, scientists say
Researchers in Japan say they’ve found proof.
doubted they even existed.
Half a century after Gree- ley’s paper published and NASA left the moon behind, in a paper published this week, Japanese researchers say they’ve found proof of the tunnels no one could see. At the close of the Apollo Japan calls its Kaguya age, just months before the orbiter the “largest lunar final moon walk in 1971, a mission since the Apollo proNASA researcher argued that gram.” It launched in 2007 vast tunnels lie beneath the with state-of-the-art instrulunar surface. ments, deployable satellites
There was good reason to and a mission to solve the think so. Lava from ancient great mysteries of the moon’s volcanoes might have bored origin. miles-long voids beneath In 2009, Kaguya drifted the moon, just like volca60 miles above the Marius noes carved out the KauHills and took a picture of mana Lava Tubes in Hawaii. large, deep hole.
What a sight a lunar lava Holes aren’t unusual on cave would be. Protected the moon’s pockmarked surfrom meteors and radiation face, but a NASA’s Lunar that bombards the surface, Reconnaissance Orbiter man- the tunnels might preserve aged to get a follow-up shot, evidence from the moon’s closer to the ground, as a early history and clues to team of Japanese and Amer- its mysterious origins. And ican researchers recounted many scientist have long in Geophysical Research Letdreamed of building bases ters last week. inside natural moon caves, “The floor of the hole where lunar explorers might extended at least several sleep safely in inflatable meters eastward and westhomes, protected from the ward under a ceiling of two storms above. other holes,” the research
But the lava tunnels of ers wrote — like the mouth the moon, like the mythiof a tunnel. cal canals of Mars, proved But the murky picture elusive. revealed no more. Did the
NASA’s Ronald Greeley cave go on for miles, like the hypothesized in 1971 that hypothetical lava tube, or one of the great channels dead-end just out of sight? in the moon’s Marius Hills It took years to find out. region might in fact be a col- The Japanese got another lapsed tunnel. But he admit- assist from the United States ted that no mission had in 2011, when NASA put twin yet photographed a lunar spacecrafts — Gravity Recovcave entrance — and some ery and Interior Laboratory, or GRAIL — in orbit around the moon.
GRAIL measured tiny fluctuations in the moon’s gravity to map out mountains and subterranean features. When it flew over the Marius Hills, the researchers wrote, it detected something long and hollow beneath the surface — extending more than 30 miles from the hole Kaguya found.
So Kaguya swung back into action. The Japanese probe blasted radar waves down onto the suspected tunnel, listening for anomalies in the echoes that came back from underground.
Over and over, Kaguya heard a distinctive pattern of echoes. The researchers think it is either the floor or ceiling of a cave — the longhoped for lava tunnel.
It is very long — 31 miles, according to Japan’s Institute of Space and Astronautical Science.
It must be ancient, and may be buried more than 300 feet below the surface. It might even contain ice or water.
If the researchers are correct, it sounds just like what the old Apollo scientists and so would-be colonists hoped for so long.
“Their existence has not been confirmed until now,” Junichi Haruyama, one of the paper’s author, told Agence France-Presse. And now that he knows the tunnel exists, he said, he looks forward to finding out what’s inside.