Nasa is investigating whether a large underground cave on the Moon could provide a safe haven for astronauts. The cave may extend beyond the Marius Hills Pit (MHP), a large hole in one of the Moon's most volcanically diverse regions.
Scientists say such a cave could one day protect astronauts from radiation and the extreme temperature swings experienced on the lunar surface.
GIMLI mission to explore the pit
The Geophysical Instruments for Marius Lunar pit Investigation (GIMLI) project, led by the Planetary Science Institute (PSI), will send scientific instruments and robots built by Honeybee Robotics to the area. The project is also being carried out in partnership with the Norwegian Space Agency.
GIMLI will use ground-penetrating radar, seismic sensors and a gravimeter to examine what lies beneath the surface. Cameras will provide images of the lunar surface and the walls of the pit. Together, the instruments will search for an underground void extending from MHP and, if one is found, help scientists determine its size.
Scientific goals and team
PSI director and chief executive Amanda Hendrix said: 'GIMLI represents the type of ambitious planetary science that PSI was built to pursue.' She added that the team is taking a scientific question studied from orbit and has developed a way to investigate it directly on the Moon.
PSI Associate Director and Senior Scientist Than Putzig said: 'It's long been a desire of mine to reintroduce intentional active-source seismic methods to planetary science, as it has essentially not been done since the Apollo astronauts conducted the first seismic surveys on the Moon.'
The mission will also examine the area around the pit. The region has a long history of volcanic activity, while the walls of MHP expose layers of regolith and lava flows that are normally hidden beneath the surface. Studying those layers could reveal how lava travelled across the Moon and whether long periods of time separated different eruptions.
Gareth Morgan, PSI senior scientist and deputy principal investigator on the GIMLI programme, said: 'Confirming a substantial lava tube would give us an insight into how volcanism operated on the moon.' He noted that lava tubes are common on Earth, so identifying them on the Moon could help scientists use knowledge of terrestrial caves to better understand lunar history.
The wider GIMLI team includes co-investigators from Boise State University, Johns Hopkins University, the Lunar and Planetary Institute and the University of Oslo.
