The findings center on a pyramid-shaped rock named "Jack_M" and scoops of material taken from a sand dune called Rocknest, where Curiosity spent about one month hanging out last September.
The information is exciting because "scientists used all of the instruments on Curiosity in one place," said David Blake, the lead author of one paper published in Science and the principal investigator for Curiosity's ChemMin instrument.
That makes this the most well-studied area on
"We know the elemental composition of the material from a tool called the Alpha Particle X-ray Spectrometer. We know the minerals in the material from the ChemMin X-ray, and we know the volatiles in the material from an instrument called the Sample Analysis at Mars (SAM)," explains Blake.
In one study, scientists found about 2% water from a scoop of soil collected at Rocknest. The material was fed into SAM and heated to 1,535 degrees Fahrenheit to release gases. These gases tell the scientists how much water was in the sample to begin with.
Mars is unique because the chemical composition of the soil is pretty much the same around the entire planet - so it's a good bet that soil in any given area is similar to soil in other areas. "It's likely that the conclusions that we draw from this material will be similar to soil found on all of Mars," said Blake.
The finding is good news for when we send people to Mars since "they could scoop up the soil anywhere on the surface, heat it just a bit, and obtain water," the study's lead author Laurie Leshin, said in a statement.
In another study, scientists learned that a rock named "Jake_M" represents a previously unknown type of Martian magma.
"Jake_M compares very closely with an uncommon terrestrial rock type known as a mugearite, typically found on ocean islands and in rift zones," Curiosity chief scientist John Grotzinger wrote in an introduction to the series of reports. "It probably originates from magmas generated by low degrees of partial melting at high pressure of possibly water-rich, chemically altered martian mantle that is different from the sources of other known martian basalts."
Since mugearites are formed in the presence of water on Earth, this adds to the growing body of research that there could be water deep beneath the surface of Mars.