New Evidence of Past Water on Mars: Implications for Astrobiology
In the seemingly desolate expanse of Mars, recent findings from the European Space Agency’s (ESA) Mars Express orbiter are rewriting our understanding of the planet’s history.
Despite its current arid appearance, Mars holds a wealth of evidence pointing to a watery past, including dried-up river channels, ancient ocean and lake beds, and valleys shaped by water erosion.
ESA’s Mars Express: Unearthing a Martian Ice Reservoir at the Equator
The latest revelation comes from the orbiter’s detection of a substantial volume of ice concentrated around the Martian equator. If melted, this vast reservoir could blanket the entire Martian landscape in 1.5 to 2.7 meters of water, marking the “most water ever found in this part of Mars, and enough to fill Earth’s Red Sea,” according to the ESA.
The discovery was made in the enigmatic region known as the Medusae Fossae Formation (MFF), located near the Martian equator.
This area has long puzzled scientists due to its wind-sculpted features spanning hundreds of kilometers. Fifteen years ago, Mars Express identified large deposits in the MFF, reaching depths of up to 2.5 kilometers, hinting at the presence of ice.
The recent radar observations, utilizing Mars Express’s MARSIS radar, have now provided additional insights. The ice deposits in the MFF are found to be even thicker than initially thought, measuring up to 3.7 kilometers.
Mars Express Radar Reveals Thicker Ice Deposits in MFF
Thomas Watters of the Smithsonian Institution, USA, lead author of the research, explained, “Excitingly, the radar signals match what we’d expect to see from layered ice, and are similar to the signals we see from Mars’s polar caps, which we know to be very ice-rich.”
The findings suggest that the layers in the MFF comprise both dust and ice, with a protective layer of dry dust or ash several hundred meters deep.
Importantly, these extensive ice reserves near the equator couldn’t have formed under Mars’s current harsh climate. Instead, they likely originated during a previous climatic epoch, challenging our understanding of Mars’s geological history.
Colin Wilson, ESA project scientist for Mars Express, emphasized the significance of these discoveries, stating, “This latest analysis challenges our understanding of the Medusae Fossae Formation, and raises as many questions as answers. How long ago did these ice deposits form, and what was Mars like at that time? If confirmed to be water ice, these massive deposits would change our understanding of Mars’ climate history. Any reservoir of ancient water would be a fascinating target for human or robotic exploration.”
