Getting to the Moon again will be a monumental challenge. But putting a human habitat on its surface? That could be even trickier. But a new study may have located a perfect spot for long-term living on the Moon.
Researchers from JAXA (Japan’s space agency) spotted a large, open lava tube in the Marius Hills region of the Moon. These massive, hollow tubes formed when a lava flow developed a hard crust, creating a roof above the still-active lava flow. When the lava stops flowing, the tunnel drains forming a massive cave system.
To detect this lava tube, JAXA researchers pored over radar data from the SELENE spacecraft. They noticed a peculiar echo pattern near Marius Hills. Here’s how the press release explains it:
A decrease in echo power followed by a large second echo peak, which they believe is evidence of a tube. The two echoes correspond to radar reflections from the moon’s surface and the floor and ceiling of the open tube. The team found similar echo patterns at several locations around the hole, indicating there may be more than one.
Researchers were using a spacecraft that wasn’t even designed to look for lava tubes. SELENE’s radar system is meant to study the origins of the Moon. Not pinpoint cave systems. To help narrow down the search, the JAXA team talked to scientists from NASA’s GRAIL mission. GRAIL gathers high-res data on the Moon’s gravitational field. This data can show areas of mass deficits – areas on the moon’s surface where mass is reduced or missing.
“Our group at Purdue used the gravity data over that area to infer that the opening was part of a larger system,” said GRAIL co-investigator Jay Melosh. “By using this complimentary technique of radar, they were able to figure out how deep and high the cavities are.”
Ok, but what’s so special about a lava tube on the Moon? First, they’re believed to be big. Real big. For the lava tube to be detected by GRAIL data it would need to be at least several kilometers long and at least one kilometer high and wide. Here’s how Philadelphia would look sitting inside one.
Credit: Purdue University/David Blair
Second, they would act as a natural shield to the harsh lunar environment. Sure, the temperature swings are absurd (212 degrees Fahrenheit during the day, -280 degrees Fahrenheit at night). But it’s the radiation from the Sun that’s the real problem. A lunar base tucked inside of a lava tube is a perfect solution. It would protect lunar settlers from the Sun’s harmful rays and also act as a shield against micrometeorites.
If the gravity results are accurate, the lava tube near the Marius Hills would be one of the best spots to house the first lunar base. We won’t know for sure until a person, or rover goes snooping around.
While Mars is the next ‘big’ goal, a visit back to the Moon is looking much more enticing again.
Featured image credit: NASA/Goddard/Arizona State University