In a major achievement for planetary scientists, a study of soil samples collected and analyzed by the Mars rover Curiosity has confirmed the presence of water in the Martian dirt.
The study — one of five using the new Mars data and published today in the journal Science — shows that the Red Planet’s soil contains 2% water by weight. This validated discovery may bode well for any future manned missions to Mars, as the mission would not need to carry as much water on the journey (which would add weight and more fuel usage). Astronauts landing on Mars could theoretically extract up to 2 pints of water (about 1 liter) per cubic foot (0.03 cubic meters) of soil.
In a Space.com interview, the study’s lead author, Laurie Leshin of Rensselaer Polytechnic Institute, in Troy, N.Y., commented:
“For me, that was a big ‘wow’ moment. I was really happy when we saw that there’s easily accessible water here in the dirt beneath your feet. And it’s probably true anywhere you go on Mars.”
Scientists had previously observed indications from surface formations of large amounts of (probably salty) water occurring at some point in Mars’ geologic past, perhaps even “seasonally”, but this is the first validation of liquid water present on the Martian surface.
Initial evidence for water in the Martian soil came from Curiosity‘s first Mars soil analysis of dirt scooped up from a location called Rocknest, in November, 2012. The soil sample was processed by Curiosity‘s on-board Sample Analysis at Mars instrument (SAM) which is similar to a mass spectrometer. The instrument heated the sample to a temperature of 1,535 °F (835 ° C) which allowed it to profile the gases that “boiled off” during this heating regime. SAM was able to identify significant amounts of oxygen, carbon dioxide, various sulfur compounds…and plenty of H20.
However, the rover’s analysis had to await confirmation by scientists back here on Earth. Today’s study confirms the initial robotic analysis.
Other Mars Findings & Curiosity’s Continuing Journey
The SAM instrument also identified a large percentage of deuterium, which is an isotope of hydrogen containing a single neutron in its nucleus (found in “heavy water”, HDO, about 1 in every 6000 water molecules), present in the Martian dirt in a ratio similar to that detected in the Martian atmosphere.
“That tells us that the dirt is acting like a bit of a sponge and absorbing water from the atmosphere,” Leshin told SPACE.com.
The instrument also detected various organic compounds in this region, which are believed to have been the result of hitch-hiking organic molecules (and not from any hidden life-form, like microbes, buried in the dirt) that reacted with perchlorate in the Martian soil. Perchlorate is a toxic compound and its pervasiveness may prove problematic for any would-be Mars landing team, despite the water. Perchlorate was previously identified on the Martian north polar surface as far back as 2008 by the Phoenix lander.
Another study released today identified a unique rock (dubbed “Jake Matijevic” in honor of a recently deceased, rover mission team member) as a type of rock never before seen on Mars, but similar to some volcanic rocks found here on Earth. The rock provides evidence that Martian geology is more differentiated and evolved than was previously thought.
“Of all the Martian rocks, this one is the most Earth-like. It’s kind of amazing,” said Curiosity lead scientist John Grotzinger, a geologist at the California Institute of Technology in Pasadena.
To date, the Mars rover has only completed about 1/5 of its planned 5.3 mile (8.5 km) journey to Mount Sharp which rises up from the center of Gale Crater. Scientists estimate it will reach reach the base of the mountain around the middle of next year. And as it travels (slowly) to its destination, Curiosity collects continuous data via its on-board array of ten scientific instruments. The instruments have held up well and are proving themselves to be rich sources of data that will no doubt provide more remarkable discoveries in the months and years ahead.
For more on these discoveries and additional research findings from Curiosity‘s first 100 days on the Red Planet, check out the Space.com (via Yahoo News) article: Curiosity Rover Makes Big Water Discovery in Mars Dirt, a ‘Wow Moment’
Top photo: (Left) close up of the Mars Rocknest site. (Right) Close up of Curiosity’s dirt sample from that site where the presence of liquid water has been confirmed (credit: NASA/JPL via Yahoo News)