The ‘John Klein’ rock surface, target for drilling. Scale of image is approximately 1 meter across. Image has been white-balanced to mimic Earth-illumination (NASA/JPL-Caltech/MSSS)

NASA’s Curiosity rover is preparing to drill for the first time, into what appears to be sedimentary rock criss-crossed by mineral-filled veins.

 

 

 

 

Back in September last year the Mars Science Laboratory carried by the rover found a rocky outcrop on the wall of Gale Crater that was full of a crusty mix of cemented pebbles. It matched signs of an alluvial-fan feature seen from orbit and was some of the very best evidence so far of significant historical water flow across the martian surface.

Light color mineral veins in martian rock – a strong clue to a water soaked past (NASA/JPL)

Now Curiosity has entered Yellowknife Bay, a terrain that exhibits all the signs of a different type of water presence. In fact this depression in the landscape seems to be entirely distinct from the earlier Gale Crater landing site about 500 meters away.

Here sedimentary rocks (formed from the crushed remains of earlier rocks) are filled with fractures and veins of what might be hydrated calcium sulfate (bassinite or gypsum) – deposited when water soaked this area. There are also nodules of deposited material, cross-bedded layering, and even a rather shiny pebble embedded in sandstone that’s provoked our human pattern recognition system into thinking there’s a martian ‘flower’ popping from the ground.

It’s the perfect place for a spot of prospecting.

Over the next few days to weeks Curiosity will try out its drill, attached to the end of its 7-foot robotic arm. The drill has a bore depth of about 5 cm, enough to get well past the weathered crust of these rocks and to retrieve the grindings of an ancient martian environment.

The drill with ‘bit’ attached. Cylindrical sheath channels material up for collection. (NASA/JPL)

It’s not an easy task. There are concerns that a Teflon coating on the drill bit may flake off – contaminating any samples. So the first task will be to sacrifice a small amount of the upper layers of rock as an abrasive ‘cleaning’ material for the drill – getting rid of any Earthly contaminants before going deeper.

Once it does we’ll have a new window onto Mars’ deep past.

‘John Klein’ site in raw color (NASA/JPL-Caltech/MSSS)

 
 

About the Author: Caleb Scharf is the director of Columbia University’s multidisciplinary Astrobiology Center. He has worked in the fields of observational cosmology, X-ray astronomy, and more recently exoplanetary science. His latest book is ‘Gravity’s Engines: How Bubble-Blowing Black Holes Rule Galaxies, Stars, and Life in the Cosmos’, and he is working on ‘The Copernicus Complex’ (both from Scientific American / Farrar, Straus and Giroux.) Follow on Twitter @caleb_scharf.More »

On December 17th 2012 two small spacecraft called Ebb and Flow punched into the lunar surface at over 3,700 miles an hour.

This ended the year long mission of NASA’s Gravity Recovery and Interior Laboratory (GRAIL). The twin spacecraft spent most of this time orbiting the Moon’s surface at a scarily low altitude of about 31 miles, sweeping in tandem above the dusty terrain never more than 140 miles apart from each other.

 

Gravity map of the Moon (Credit: NASA/JPL-Caltech/MIT/GSFC)

Microwave telemetry between the spacecraft, the Earth, and the application of basic geometry let GRAIL monitor the distance between Ebb and Flow to a precision of about a tenth of a micron – half the width of a human hair.

As with any planet or satellite the Moon’s gravitational field is not perfectly symmetrical. Variations in the density and height of material produce tiny variations in the gravitational acceleration felt by other objects. By sensing Ebb and Flow’s varying movement in orbit a detailed map of the lunar gravity field was constructed. With a knowledge of the topographic features on the surface this can be turned into the equivalent of a medical tomographic reconstruction of the lunar interior – and it’s lumps and bumps.

The data is amazing, but GRAIL had one last gift to give. In the days leading up to their crash on the lunar surface the spacecraft returned imagery from their ever lowering orbits.

This is the quite surreal and beautiful timelapse footage taken by Ebb as it skimmed across part of the northern terrain of the Moon’s far side at an altitude of only 6 miles on December 14th 2012. Enjoy.

 

 
 

About the Author: Caleb Scharf is the director of Columbia University’s multidisciplinary Astrobiology Center. He has worked in the fields of observational cosmology, X-ray astronomy, and more recently exoplanetary science. His latest book is ‘Gravity’s Engines: How Bubble-Blowing Black Holes Rule Galaxies, Stars, and Life in the Cosmos’, and he is working on ‘The Copernicus Complex’ (both from Scientific American / Farrar, Straus and Giroux.) Follow on Twitter @caleb_scharf.More »