The neighbourhood is a wild card, and moving there is bound to be expensive. But one of the best options for shelter when humans finally make it to the red planet will be subterranean caves. These rocky hollows, which exist in droves on both Earth and the moon, are natural buffers against the harsh conditions of Mars.
At the recent Geological Society of America Connects 2022 meeting in Denver, researchers pinpointed nine leading cave candidates worthy of future exploration. All of these grottos appear to extend at least some distance underground, and they’re close to landing sites accessible to a lightweight rover.
These structures would offer a respite from the challenging Martian environment, said Nicole Bardabelias, a geoscientist at the University of Arizona. “Everything at the surface is subject to harsh radiation, possible meteorite or micrometeorite bombardment and really large day-to-night temperature swings,” she said.
To home in on Mars’ most sought-after real estate, Bardabelias and her colleagues consulted the Mars Global Cave Candidate Catalog. This compendium, based on imagery collected by instruments aboard the Mars Odyssey spacecraft and the Mars Reconnaissance Orbiter, inventories over 1,000 candidate caves and other peculiar-looking features.
The researchers narrowed the catalog by imposing two criteria. First, they required that a cave be within roughly 60 miles of a suitable spacecraft landing site. Second, they stipulated that high-resolution imagery be available.
Bardabelias and her collaborators defined a suitable landing site as one below an elevation of roughly 3,300 feet.
The team required that top-shelf imagery be available for each cave candidate. That honour belongs to HiRISE, or the High Resolution Imaging Science Experiment camera aboard the Mars Reconnaissance Orbiter.
There were 139 apparent caves that satisfied the team’s criteria, and Bardabelias and her collaborators manually examined images of each one. After disregarding features such as bridge-shaped rock formations that obviously weren’t caves, the team analysed the remaining pitlike features. The researchers homed in on only those that appeared to extend some distance underground, which yielded a sample of nine leading cave candidates.
These potential caves are worth a closer look, Bardabelias said. But none of the rovers operating on Mars are close enough to explore any, so that task falls to spacecraft orbiting the red planet. Follow-up HiRISE images taken from different angles and in different lighting conditions will reveal new details about these caves, Bardabelias said. — AFP