sciencetech-blog

comments

How did the mountain known as Mount Sharp come to be in the centre of the Gale Crater on Mars, and just how habitable was this area in the past?

That's what the team operating Nasa's Curiosity rover will be hoping to discover after spending the weekend inspecting a potential drilling site.

The site contains a sandstone slab known as Windjana, named after a gorge in Western Australia, that could provide much-needed answers to some intriguing questions about life on Mars.

This image, taken at the end of last week with the Curiosity rover's Mast Camera (Mastcam), shows a sandstone slab at the centre. The rover team has spent the weekend getting Curiosity to examine a target patch on the rock, called 'Windjana,' with a view to studying it further

If this target meets criteria set by engineers and scientists, it could become the mission's third drilled rock - and the first to be carried out on sandstone, rather than mudstone.

From planned drilling at Windjana, Curiosity's science team hopes to analyse the cement that holds together the sand-size grains in the rock - and learn more about the habitability of the region.

The planned inspection, designed to aid a decision on whether to drill at Windjana, includes observations with the camera and X-ray spectrometer at the end of the rover's arm.

A brush to remove dust from a patch on the rock was also used, and readings of composition at various points on the rock were made using an instrument that fires laser shots from the rover's mast.

Curiosity's hammering drill collects powdered sample material from the interior of a rock, and then the rover prepares and delivers portions of the sample to onboard lab instruments.

The first two Martian rocks drilled and analysed this way were mudstone slabs neighbouring each other in Yellowknife Bay, about 2.5 miles (4 kilometres) northeast of the rover's current location at a waypoint called 'the Kimberley.'

Those two rocks yielded evidence of an ancient lakebed environment with key chemical elements, and a chemical energy source that provided conditions billions of years ago favourable for microbial life.

It is hoped Windjana could provide similar information into the previous habitability of Mars.

'We want to learn more about the wet process that turned sand deposits into sandstone here,' said Curiosity Project Scientist John Grotzinger, of the California Institute of Technology in Pasadena.

'What was the composition of the fluids that bound the grains together? That aqueous chemistry is part of the habitability story we're investigating.'

The target is on the approximately two-foot-wide (60 centimetres) rock seen in the right half of this view. The sandstone target's informal name comes from Windjana Gorge in Western Australia. If this target meets criteria set by scientists, it could become the mission's third drilled rock and the first that is not mudstone

This view is an excerpt from an 11 April 2014 observation by Nasa's Mars Reconnaissance Orbiter. In the lower centre of the screen, by the red dot, is 'Mount Remarkable' that stands 16 ft (5m) high, with Windjana nearby. Curiosity appears as the bright blue object at the two-o'clock position relative to the dot

Understanding why some sandstones in the area are harder than others also could help explain major shapes of the landscape where Curiosity is working inside Gale Crater.

Erosion-resistant sandstone forms a capping layer of mesas - hills shaped like table-tops - and buttes - isolated hills with steep sides and flat tops.

It could even hold hints about why Gale Crater has a large layered mountain, Mount Sharp, at its centre.

Nasa's Mars Science Laboratory (MSL) project is using Curiosity to assess ancient habitable environments and major changes in Martian environmental conditions.

Over the weekend Curiosity extended its arm to Windjana to ascertain whether it is worthwhile drilling there. The rock is within a waypoint location called 'the Kimberley,' where sandstone outcrops with differing resistance to wind erosion result in a stair-step pattern of layers

The team must now decide if the rock, pictured, is worthy of further study. Drilling operations can take weeks to plan and execute, which is why so much preparation is needed. Ultimately this seemingly inconspicuous sandstone could explain how Mount Sharp, Curiosity's ultimate destination, formed in the Gale Crater

The Curiosity rover, pictured, landed on Mars on 6 August 2012 and has been exploring its fascinating surroundings ever since. Nasa's Jet Propulsion Laboratory, a division of Caltech, built the rover and manages the project for Nasa's Science Mission Directorate in Washington