Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more.
(CNN)Exploring beneath the surface of other planets may be the key to determining whether life has ever existed outside of Earth.
As other missions, including that of NASA’s InSight lander, have shown, drilling down through the surface of planets like Mars is tough — a little too tough to get more than a few inches into the subsurface.
Recently, the Curiosity rover measured total organic carbon, a necessary ingredient in the molecules of life, in Martian rocks for the first time. But it doesn’t prove that life ever existed on Mars, because carbon can also be produced by nonliving sources.
New research suggests that the best chance of finding past or present evidence of life on Mars requires going below its surface — at least 6.6 feet (2 meters) below. Mars has an incredibly thin atmosphere, which means that the surface of the red planet is bombarded by high energy radiation from space, and that could quickly degrade substances like amino acids that provide fragile evidence of life.
Those harsh surface conditions also present a challenge for astronauts, which is one reason scientists have suggested that caves on other planets could be the key to future exploration. Vast cave systems on the moon and Mars could act as shelters for future space travelers.
Caves could also contain resources like water, reveal more about the history of a planet — and be havens for evidence of microbial life. On Earth, there are a varied range of cave systems, many of which remain unexplored, and they support diverse groups of microorganisms. But caves are dangerous — and since we’ve never peered inside a Martian cave, it’s difficult to know what to expect.
Before humans land on Mars and explore its subsurface, a group of scientists want to send ReachBot — a robot designed to crawl and climb through extraterrestrial caves.
Continue Reading: CNN