NASA says its Mars Curiosity rover has identified a mineral it drilled from the Red Planet's surface that matches what instruments on the space agency's Mars Reconnaissance Orbiter had seen from space and which hints at the planet's past habitability.
The iron-oxide mineral known as hematite had been detected by a spectrometer aboard the MRO inside Gale Crater two years before that site was chosen for Curiosity's 2012 landing.
As the rover has been ascending from the crater floor to the base of Mount Sharp, which sits inside the crater, is has been taking soil and rock samples.
Its most recent sample of some reddish rock powder revealed the hematite in the mission's first confirmation of a mineral mapped from orbit.
"We've reached the part of the crater where we have the mineralogical information that was important in selection of Gale Crater as the landing site," says Curiosity science team member Ralph Milliken of Brown University in Rhode Island.
The discovery can provide clues to understanding the environmental conditions -- possible even habitable conditions -- the hematite could have formed in, the scientists say.
Hematite is formed as another mineral, magnetite, oxidizes during exposure to Mars' atmosphere and water, and is further evidence the Red Planet was once much wetter than it is now.
The MRO data has been a valuable tool to guide Curiosity's explorations, Milliken says.
"We're now on a path where the orbital data can help us predict what minerals we'll find and make good choices about where to drill," he says.
Working with instruments on the rover, which operates on the time scale of Martian days -- each about 40 minutes longer than our Earth days -- can result in some odd working conditions, points out one researcher who has found herself having a job any graduate student like herself might only dream about.
Shaunna Morrison wears two hats, as a mineralogy graduate student at the University of Arizona who has also spent the last 2 years working at NASA's Jet Propulsion Laboratory in Pasadena, Calif., as a member of the rover science team.
Her job at JPL concerns an instrument on the rover called CheMin, for Chemistry and Mineralogy, the instruments that has identified the hematite.
Trying to work to Mars time, which goes in and out of synchronization with Earth time, means Morrison's work schedule is anything but regular, rotating around the clock.
"Going in to work everyday takes on a new meaning when your office is on Mars," she says.
It may start at 9 a.m. one day, but three weeks later it will be starting at 9 p.m., and after a month she may begin work at 3 a.m.
"Needless to say, combining seven days a week of long shifts (16-18 hours, at times) with Mars time meant we all drank a lot of coffee," she says.
Still, she says, the discoveries Curiosity is making -- like the recently identified hematite and its suggestion of a previously habitable Mars -- make it all worthwhile.
"Exploring the unknown and searching for answers to the universe's biggest questions -- this is what dreams are made of," she says. "My dreams, at least."
