Potential human habitat located on the moonStaff Writer | October 19, 2017
A study published in Geophysical Research Letters confirms the existence of a large open lava tube in the Marius Hills region of the moon, which could be used to protect astronauts from hazardous conditions on the surface.
Space The two echoes correspond to radar reflections
Unlike Earth, the moon has no atmosphere or magnetic field to protects its inhabitants.
The safest place to seek shelter is the inside of an intact lava tube, according to the study.
Lava tubes are naturally occurring channels formed when a lava flow develops a hard crust, which thickens and forms a roof above the still-flowing lava stream.
Once the lava stops flowing, the tunnel sometimes drains, forming a hollow void.
"It's important to know where and how big lunar lava tubes are if we're ever going to construct a lunar base," said Junichi Haruyama, a senior researcher at JAXA, Japan's space agency.
"But knowing these things is also important for basic science. We might get new types of rock samples, heat flow data and lunar quake observation data."
JAXA analyzed radar data from the SELENE spacecraft to detect underlying lava tubes. Near the Marius Hills Skylight, an entrance to the tube, they found a distinctive echo pattern: 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.
SELENE's radar system wasn't designed to detect lava tubes - it was built to study the origins of the moon and its geologic evolution.
For these reasons, it didn't fly close enough to the moon's surface to get extremely accurate information on what is (or isn't) underneath.
When the JAXA team decided to use their data to try and find lava tubes, they consulted scientists from the GRAIL mission, a NASA effort to collect high-quality data on the moon's gravitational field.
By surveying the areas where GRAIL had identified mass deficits, or less mass under the surface, they narrowed down the data they needed to analyze. ■