Mars hydrothermal deposits hint at habitable conditions
A recent report in Nature Communications indicates that ancient Mars may have had deep sea-floor hydrothermal activity. Hydrothermal deposits on Earth are associated with the earliest signs of life and habitable environments today. Their detection on Mars has implications for the possibility of ancient life on the Red Planet.
The report is based on infrared spectroscopy and high-resolution imaging observations from NASA’s Mars Reconnaissance Orbiter’s Compact Reconnaissance Spectrometer for Mars instrument. The report created by an international team of researchers focused on the Eridania basin the southern hemisphere of Mars. They determined that the Eridania basin – composed of Noachian Era crust aged 3.7–4.1 billion years old – may have held a large ancient sea 3,609 feet (1,100 meters) deep. The total volume would have been approximately 50,000 cubic miles (210,000 cubic kilometers) of water, or ten times more water than all of the Great Lakes combined.
In addition, a number of minerals typically found in and around deep water hydrothermal vents on Earth were also found in this area of Mars. The estimated time when these minerals were deposited on Mars also correlates with the time during Earth’s evolution when early life is thought to have begun at deep sea-floor hydrothermal vents, approximately 3.7 billion years ago.
These new observations of suspected hydrothermal vents add to the known types of wet environments that are believed to have once existed on Mars, including rivers, lakes, deltas, seas, and groundwater. Currently, Mars has no standing liquid water, nor any known volcanic activity, although mounting evidence is proving that it once did. The Red Planet has gone through widespread global changes in the more than 3 billion years since this Martian sea is believed to have existed. In that time the temperature has changed as well as the surface pressures required to maintain water as a liquid on the surface of the planet.
“This site gives us a compelling story for a deep, long-lived sea and a deep-sea hydrothermal environment,” said Paul Niles of NASA’s Johnson Space Center, Houston. “It is evocative of the deep-sea hydrothermal environments on Earth, similar to environments where life might be found on other worlds – life that doesn’t need a nice atmosphere or temperate surface, but just rocks, heat and water.”
Scientists believe that the development of life is directly linked to the presence of liquid water, which allows for the movement and exchange of nutrients and waste. If Mars did have standing water, along with the energy and nutrients that occur at and around hydrothermal vents and hot springs, then this not only provides intriguing clues to Mars’ distant past but also hints at the tantalizing increased possibility for early ancient life developing on Mars independent of Earth.
“Ancient, deep-water hydrothermal deposits in Eridania basin represent a new category of astrobiological target[s] on Mars,” the report states. “Eridania seafloor deposits are not only of interest for Mars exploration, they represent a window into early Earth.” The earliest evidence of life on Earth comes from seafloor deposits of similar origin and age; however, the geological record of those early-Earth environments is poorly preserved.
Despite Mars’ current cold, dry, and seemingly geologically inactive environment, these findings point to a time during the boundary between Mars’ late Noachian and early Hesperian eras about 3.7 billion years ago when conditions were warmer and wetter. The stark difference between Mars in the present day and the past conditions recorded in Eridania increases the possibility of habitable conditions on Mars.
A native of the Greater Los Angeles area, Ocean McIntyre's writing is focused primarily on science (STEM and STEAM) education and public outreach. McIntyre is a NASA/JPL Solar System Ambassador as well as holding memberships with The Planetary Society, Los Angeles Astronomical Society, and is a founding member of SafePlaceForSpace.org. McIntyre is currently studying astrophysics and planetary science with additional interests in astrobiology, cosmology and directed energy propulsion technology. With SpaceFlight Insider seeking to expand the amount of science articles it produces, McIntyre was a welcomed addition to our growing team.