NASA Mars Rover Curiosity breaks Tintina rock reveals dazzling white interior

When Curiosity drove over Tintina, the rock broke apart and exposed a fresh, bright white surface

A rock crushed under the Curiosity Mars rover's wheels has dazzled mission scientists in more ways than one.

Mars is supposed to be the Red Planet, but the rock - dubbed "Tintina" - is a brilliant shade of white.

The unusual colour indicates the presence of hydrated minerals that formed when water flowed through the robot's landing site in ancient times.

Water-bearing minerals in Tintina and elsewhere add to the growing catalogue of water evidence at this location.

Rover team members have been presenting mission findings at the 44th Lunar and Planetary Science Conference (LPSC) in The Woodlands, Texas.

It was also announced that the rover has suffered another computer glitch; Curiosity had already been recovering from a memory problem discovered earlier in the month.

The description of hydrated minerals at Gale Crater follows an announcement last week that Curiosity had found clay minerals in a rock it had drilled.

These clays indicate formation in, or substantial alteration by, neutral water.

That is significant for showing that conditions on the Red Planet could have supported life in the distant past, because many rocks studied previously were probably deposited in acidic water.

Speaking here in The Woodlands, near Houston, chief scientist John Grotzinger described Curiosity's landing site as the first truly habitable environment found on Mars.

"What we're really excited about is that this is the first time we've been able to follow through with a whole suite of different measurements that really demonstrate the place we found at Gale Crater was a very viable, habitable environment," he reported.

Prof Grotzinger added that the team "felt really good" about the Martian location.

The one-tonne Nasa rover has been exploring Gale Crater, near the Martian equator, since touching down in August 2012. It drove over Tintina on 17 January, breaking it open to expose the dazzling white interior.

"This is one of the brightest and whitest things we've seen with the Mastcam at the Gale Crater site," said Melissa Rice, from the California Institute of Technology (Caltech), in Pasadena.

"This rock, Tintina, has a very strong hydration signal that corresponds to all that white material we see inside the rock. But that hydration signal doesn't show up anywhere else in the image.

"The first time we tried to take the image [of Tintina], it saturated the detector, because we had no idea we'd have something so bright," said Jim Bell, from Arizona State University in Tempe.

Using filters on the rover's Mast camera (Mastcam) and an instrument which shoots neutrons into the ground to probe for hydrogen, researchers have detected more hydrated minerals near the clay-bearing rock than at locations Curiosity visited earlier in its mission.

Melissa Rice explained: "What Mastcam is seeing is water that is bound in the mineral structure of the rocks. This water is left over from a previous wet era and is now trapped and preserved in these hydrated minerals."

NASA Mars Rover Curiosity: Trend in Water Presence

Hydration Map, Based on Mastcam Spectra, for 'Knorr' Rock Target: On this image of the rock target "Knorr," colour coding maps the amount of mineral hydration indicated by a ratio of near-infrared reflectance intensities measured by the Mast Camera (Mastcam) on NASA's Mars rover Curiosity. 

Credit: NASA/JPL-Caltech/ MSSS/ ASU

NASA's Mars rover Curiosity has seen evidence of water-bearing minerals in rocks near where it had already found clay minerals inside a drilled rock.

Last week, the rover's science team announced that analysis of powder from a drilled mudstone rock on Mars indicates past environmental conditions that were favorable for microbial life.

Additional findings presented today (March 18) at a news briefing at the Lunar and Planetary Science Conference in The Woodlands, Texas, suggest those conditions extended beyond the site of the drilling.

Using infrared-imaging capability of a camera on the rover and an instrument that shoots neutrons into the ground to probe for hydrogen, researchers have found more hydration of minerals near the clay-bearing rock than at locations Curiosity visited earlier.

The rover's Mast Camera (Mastcam) can also serve as a mineral-detecting and hydration-detecting tool, reported Jim Bell of Arizona State University, Tempe.

"Some iron-bearing rocks and minerals can be detected and mapped using the Mastcam's near-infrared filters."

Ratios of brightness in different Mastcam near-infrared wavelengths can indicate the presence of some hydrated minerals.

The technique was used to check rocks in the "Yellowknife Bay" area where Curiosity's drill last month collected the first powder from the interior of a rock on Mars.

Some rocks in Yellowknife Bay are crisscrossed with bright veins.

"With Mastcam, we see elevated hydration signals in the narrow veins that cut many of the rocks in this area," said Melissa Rice of the California Institute of Technology, Pasadena.

"These bright veins contain hydrated minerals that are different from the clay minerals in the surrounding rock matrix."

The Russian-made Dynamic Albedo of Neutrons (DAN) instrument on Curiosity detects hydrogen beneath the rover.

At the rover's very dry study area on Mars, the detected hydrogen is mainly in water molecules bound into minerals.

"We definitely see signal variation along the traverse from the landing point to Yellowknife Bay," said DAN Deputy Principal Investigator Maxim Litvak of the Space Research Institute, Moscow.

"More water is detected at Yellowknife Bay than earlier on the route. Even within Yellowknife Bay, we see significant variation."

Findings presented today from the Canadian-made Alpha Particle X-ray Spectrometer (APXS) on Curiosity's arm indicate that the wet environmental processes that produced clay at Yellowknife Bay did so without much change in the overall mix of chemical elements present.

The elemental composition of the outcrop Curiosity drilled into matches the composition of basalt. For example, it has basalt-like proportions of silicon, aluminum, magnesium and iron.

Basalt is the most common rock type on Mars. It is igneous, but it is also thought to be the parent material for sedimentary rocks Curiosity has examined.

"The elemental composition of rocks in Yellowknife Bay wasn't changed much by mineral alteration," said Curiosity science team member Mariek Schmidt of Brock University, Saint Catharines, Ontario, Canada.

A dust coating on rocks had made the composition detected by APXS not quite a match for basalt until Curiosity used a brush to sweep the dust away. After that, APXS saw less sulfur.

"By removing the dust, we've got a better reading that pushes the classification toward basaltic composition," Schmidt said.

The sedimentary rocks at Yellowknife Bay likely formed when original basaltic rocks were broken into fragments, transported, re-deposited as sedimentary particles, and mineralogically altered by exposure to water.