Discovery of More Ponds on Mars Hints at Possibility of Life
Two years after discovering a large, subterranean lake on Mars, a team of scientists has reaffirmed its original finding and identified three additional ponds using reflectance data from a spacecraft orbiting the planet. The results, published September 28 in Nature Astronomy, suggest that the red planet is home to several liquid bodies of water, kept from freezing due to their high salt content. If confirmed by further research, the south pole of Mars could become a strong target in the search for extraterrestrial life.
“Not only did we confirm the position, extent and strength of the [results] from our 2018 study, but we found three new bright areas” generated by the ponds, Elena Pettinelli, a geophysicist at Roma Tre University in Italy and a coauthor on the new study, tells BBC News.
Compared to Pettinelli and colleagues’ previous work, the new study includes a wider area, imaged with finer detail over a longer period of time. Previously, the lake was identified based on 29 observations made between 2012 and 2015. The current study includes 134 observations taken across 75,000 square kilometres from 2012 to 2019, Nature reports.
To visualize the lake and the three ponds, which are hidden more than one mile beneath the planet’s frozen surface, the team relied on technology used to study lakes buried under the ice at the Earth’s poles, according to the Associated Press. The observations were made using a radar sounder on the European Space Agency’s Mars Express orbiter called the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS). MARSIS bounces radio waves off the surface and subsurface of Mars. The properties of the signals that return to the satellite, such as its reflectance, tell scientists something about the nature of the terrain below.
The identification of the lake in 2018 began “a new line of inquiry that’s very exciting,” Jim Green, NASA’s chief scientist, told Nature at the time. Its confirmation now lends even greater weight to the idea that Mars can in fact support liquid water. In the newest study, the team was able to further detail the lake’s proportions—roughly 18.6 by 12.4 miles in area.