Curiosity uncovers surprising amount water in Martian soil

The National Aeronautics and Space Administration (NASA) has found water on Mars.

Analysis by the rover Curiosity revealed that soil on Mars contains two percent water by weight, meaning that one cubic foot of soil could yield two pints of water.

These results were published in the journal “Science” on Sept. 26. In an interview with, lead author Laurie Leshin (Rensselaer Polytechnic Institute) said, “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.”

Curiosity has been roving Mars since August 2012. Its mission includes looking for evidence of conditions hospitable to life, analyzing climate and geology and assessing the feasibility of human exploration of the planet.

The soil sampled comes from the Rocknest site in the Gale crater,which is near Mars’ equator and in the region of Curiosity’s study. Curiosity touched down at the Bradbury landing site inside the crater and is currently driving toward Aeolis Mons, unofficially known as Mount Sharp, a 3.4-mile-high mountain located in the crater’s center. Scientists hope to investigate Martian geology by studying sediments as the rover scales the mountain.

This discovery confirms previous estimates of water content on the Mars’ surface. These previous estimates were based on observations from the Mars Odyssey probe taken while orbiting the planet. While Curiosity’s measurements are on the low end of the previously estimated range (between two percent and 12 percent), scientists estimate that water content on Mars’ surface increases with latitude.

Scientists used Curiosity’s Sample Analysis at Mars (SAM) instruments to analyze the soil. Scientists heated soil samples to 835 degrees Celsius (1535 degrees Fahrenheit) and measured the gases released. Water, carbon dioxide, sulfur dioxide and oxygen were the most abundant gases found in each sample.

Curiosity has uncovered evidence of ancient rivers and lakes on the red planet. Early in its mission, the rover discovered a streambed through which water, billions of years ago, flowed knee-deep. The turbulent water left telltale “dunes” like one might observe in rivers on Earth. The discovery of a mudstone containing clay minerals caused scientists to infer that lakes must have existed for that particular type of stone to form.

While these water-related discoveries are promising for showing that Mars at one time could have supported life, the sum of the evidence is inconclusive. Curiosity detected no methane in Mars’ atmosphere. The finding was surprising as earlier measurements taken from Earth suggested that certain areas on Mars contained methane.

While this doesn’t rule out the possibility of life, organisms produce 99 percent of methane on Earth and such a finding would have given researchers a stronger clue as to the existence of life on Mars. Scientists, however, have found evidence that Mars at one time had a warmer, wetter climate and a thicker atmosphere, all pointing to the possibility of life.

Though NASA has furloughed 97 percent of its employees in light of the federal government shutdown, Curiosity’s operations will continue as normal. John Grotzinger, a scientist working on Curiosity, told NPR in an email, “We are still driving. … All [Jet Propulsion Laboratory] employees are Caltech employees. We have 13 countries represented on the mission and their citizens do a lot of work. And, yes, there are fair number of academics — both professors and graduate students. U.S. civil servants are actually a minority of the team.”