MADRID – The Mars rover Curiosity has found indications of the possible presence of saltwater just 5 centimeters (2 in.) below the Martian surface, according to an article in the latest issue of Nature Geoscience.
One of Curiosity’s objectives is to determine whether Mars can, or ever could, support life. Since landing on the planet in August 2012, the rover has sent data showing methane fluctuations in the atmosphere and fixed nitrogen – the only form that can be used by living organisms – in soil sediment.
Those findings could point to biological activity.
Two instruments aboard the Curiosity, the Spanish-made REMS and the Russian DAN, have revealed that the Gale crater, in the equatorial region of Mars, has the conditions for the presence of brine.
“This is the first time we find evidence that conditions exist on Mars for the formation of liquid water,” study author Javier Martin Torres told Efe, while adding that those conditions occur only at night.
During the Martian summer, the temperature in the equatorial region can plunge from 20 C (70 F) during the day to minus 73 C (minus 100 F) at night. Humidity also fluctuates, between 100 percent before dawn to 0 percent after sunrise.
Martin Torres, of the Andalusian Institute of Earth Sciences, said Curiosity has collected data over one Martian year – equivalent to two years on Earth – about humidity, temperature and air pressure.
The analysis of that data has given researchers clues pointing to the possible existence of brine.
Salts present on Mars’ surface could be absorbing the atmospheric humidity during the night to form water that evaporates after sunrise, he said.
Liquid water is a requisite for life as we know it, but other environmental conditions on Mars could make life unsustainable: temperatures at Gale are too low for metabolism and cellular reproduction as they happen on Earth, Martin Torres said.
“Nevertheless, the possible existence of liquid water on Mars has enormous implications for habitability on the planet, its future exploration and for geological processes related to water,” the scientist said.