NASA, in its endless quest to understand our cosmic neighborhood, continues to explore Mars. Their latest discovery is an underground lake that they believe holds water. While many believe that Mars holds the promise of evidence of extraterrestrial life, water has been surprisingly elusive. Now, though, that may change.
“Radar scans of the red planet suggest that a stable reservoir of salty, liquid water measuring some 12 miles across lies nearly a mile beneath the planet’s south pole,” National Geographic writes. “What’s more, the underground lake is not likely to be alone.”
“There are other areas that seem to be similar. There’s no reason to say this is the only one,” Elena Pettinelli of Italy’s Roma Tre University says. She’s coauthor of the article detailing the find in the journal Science.
Scientists believe that the planet once held vast oceans. The underground lake may hold information about where those lakes disappeared to, and when, and astrobiologists are optimistic that they may contain life or evidence of life.
“In this kind of environment that we know of on Earth, in the Antarctic, we have bacteria,” Pettinelli told NG. “They can be deep in the ice.”
This isn’t the first discovery of water on mars, but it may be the largest quantity. “Scientists have found water on Mars multiple times, but it’s usually quite transient or inaccessible, either hovering in the atmosphere, locked into permafrost or polar caps, or perhaps seasonally seeping down crater slopes. And the amount we’ve found doesn’t quite fill those ancient Martian seas or make crop-growing particularly easy,” NG adds.
In order to dig deeper, so-to-speak, scientists have been relying on low-frequency radio waves. When beamed at the surface of mars, they penetrate the surface and bounce back when they encounter something beneath the surface. This radical oversimplification results in a return pattern that scientists are then able to read.
By comparing those signals to the known signals we can generate on earth, the team has some good comparisons to evaluate the data they receive. Scientists studied the way our polar regions reflected the radar, knowing that water trapped beneath the ice gives off a predictable signal. When compared to what they received from Mars, they found a match.
“We knew that there was something there, and we were curious to know what was under that area,” Pettinelli notes. “And we were stubborn enough to do the data analysis.”
So is it a lake? It may be just water trapped in sediment beneath the surface.
“We can’t choose between one or the other. We don’t have enough information to say this is a lake or saturated sediment like an aquifer,” Pettinelli says. “The lake will be more interesting.”
“I think, we’ve done a good job in trying to kill this idea, in the sense that we have been trying to destroy the possibility that it was water many times,” Pettinelli says. “So we are quite convinced now, and we hope to be more convinced in the future with other data.”