New evidence of water on Mars renews hope in the search for life, scientists say
According to calculations, the liquid equivalent to that found 1-2 km deep in the ocean could be frozen up to 20 km below the surface.
Scientists say that more than three billion years ago Mars had lakes, rivers and oceans on its surface - Photo Reproduction / vrcraft / Getty Images / iStockphoto
Scientists around the world are celebrating the discovery of new evidence of water on Mars, a find that could transform the search for extraterrestrial life. Recent research suggests that there are large reserves of underground water on the red planet, which rekindles hope that Mars may harbor microbial life forms, or at least has in the past.
The researchers claim that, more than 3 billion years ago, Mars had not only lakes and rivers, but also vast oceans on its surface. However, as the planet lost its atmosphere, these bodies of water disappeared. Today, what remains visible are layers of permafrost (soil that is frozen all year round) at the planet's poles. Although some of the water is believed to have been lost to space, research indicates that this is not the full story. Water may have been embedded in minerals, buried as ice, or even existed in liquid form deep within the planet's crust.
The New Discoveries
Studies indicate that large volumes of liquid water may be trapped in rocks at a depth of approximately 11.5 to 20 km below the surface of Mars. According to Dr. Vashan Wright, co-author of the study from the Scripps Institution of Oceanography at the University of California, San Diego, the estimate of liquid water is greater than the volumes of water needed to fill the possible ancient oceans of Mars. The new evidence came through analysis of data collected by NASA's InSight lander, a space probe that was designed to measure the planet's tremors and rumbles and help scientists map the interior of the Martian soil.
Writing in Proceedings of the National Academy of Sciences, Wright and his colleagues describe how they performed calculations based on Mars gravity data and measurements recorded by the InSight lander. These data show how the speed of seismic waves generated by earthquakes and meteorite impacts on Mars varies with depth in the red planet's crust.
“A middle crust whose rocks are cracked and filled with liquid water best explains the seismic and gravitational data,” Wright said.
Wright said that if measurements taken at the InSight landing site are indicative of the entire planet, the amount of water trapped in rock fractures would be enough to form an ocean between 1 and 2 km deep on Mars. He explained that on Earth, groundwater penetrated from the surface and a similar process is expected to have occurred on Mars. The infiltration must have occurred at a time when the upper crust was warmer than it is today.
Implications for the Search for Life
The discovery is of great relevance, because, although the presence of frozen water on Mars is already known, the confirmation of liquid water is a significant advance. The existence of liquid water is fundamental to life as we know it, and its presence considerably increases the possibility that Mars was or still is habitable.
Although the results do not discard the possibility that water was lost to space or trapped in minerals, Wright highlighted that the study allowed scientists to reassess the relative importance of these different mechanisms in the loss of water from the Martian surface over time. Although the presence of water does not guarantee the existence of life, water is believed to be an essential component for life, Wright explained.
"We know that life can thrive in Earth's deep subsurface, where there is water. Mars' mid-crust has at least one of the fundamental ingredients for habitability and life as we know it, he said.
The presence of water could also provide clues about Mars' climate and geology, helping scientists better understand the planet's environmental history. Bethany Ehlmann, professor of planetary science at the Keck Institute for Space Studies and not directly involved in the research, said it is crucial to make a definitive measurement to determine the presence and exact location of deep liquid water on Mars. She highlighted that, on Earth, liquid water is an indication of life, and if liquid water aquifers are confirmed on Mars, they become a priority target in the search for signs of life.
Dr. Jon Wade, from the University of Oxford, said he wouldn't be surprised if we found life on Mars. According to him, at the beginning of its history, Mars could have been as favorable to simple life as Earth, or even more so. Dr. Steven Banham of Imperial College London added that the discovery of liquid water in Mars' mid-crust could help geophysicists and geologists understand the planet's internal structure and behavior. However, Banham expressed doubts about the viability of this water as a resource for manned missions to Mars. Although the amount of water in the crust is potentially vast, he highlighted that it may be difficult to access or utilize, and that this may not have a significant impact on human exploration, at least initially.
