One woman's quest for geological understanding!

“Adventures of a field geologist on Mars” – Herdman Symposium 2015

Curiosity Self-Portrait at ‘Mojave’ on Mount Sharp

I saw it announced and thought nothing more than “that sounds interesting”: We have all heard about the Curiosity Rover, which landed on Mars in 2012 and, since then,  has uncovered geologic evidence of an environment that may have supported microbial life early in the planet’s history.

I had NOT sat down to consider the time difference between Earth & Mars (A sidereal day on Mars lasts 24 hours 37 minutes and 22 seconds – ie that is the length of time for the planet to rotate once on its axis, compared to the 24 hours on Earth).  Nor had I considered that this time difference (obviously, in hindsight) meant that the lucky scientists working with the robot were on crazy shifts and that any decisions and work undertaken put them under considerable time pressure on a day-to-day basis.  Every move of the robot needs to be planned out in detail, and then run by the engineers (in terms of wear and tear of the robot, capabilities, etc.).

A chorus of oohs and aahs filled the auditorium as the first photos were presented.  Cross-Stratification / Cross-Bedding has NEVER been so exciting!  Evidence of water on Mars!  Simply mind-blowing!

(Please note that the following photos are taken from the image stock on the Mars Science Laboratory website, and are not necessarily those presented – there are soooo many to go through, and some in 3D (!), but these will give you an idea of what is on Mars!)

“Cross-bedding seen in the layers of this Martian rock is evidence of movement of water recorded by the waves or ripples of loose sediment the water passed over, such as a current in a lake. This image was acquired by the Mastcam on NASA’s Curiosity Mars rover on Nov. 2, 2014.

Cross-bedding seen in the layers of this Martian rock is evidence of movement of water recorded by waves or ripples of loose sediment the water passed over.

This image was acquired by the Mast Camera (Mastcam) on NASA’s Curiosity Mars rover, at a target called “Whale Rock” in the basal geological unit of Mount Sharp. The Mastcam’s left-eye camera took it during the 796th Martian day, or sol, of Curiosity’s work on Mars (Nov. 2, 2014).

The color has been approximately white-balanced to resemble how the scene would appear under daytime lighting conditions on Earth. Figure A is a cropped version with a superimposed scale bar of 30 centimeters (about 12 inches) just beneath cross-bedding, which is evident in the layers at angles to each other.

This example of cross-bedding shows evidence of small “climbing” ripples that migrate on top of each other (just above “10” in scale bar of Figure A [pictured above]). This suggests currents of water entered into a lake basin, possibly flowing down the front of a delta, and then spread out across the lake floor, slowing down, and depositing sediment.

The location of Whale Rock within the “Pahrump Hills” outcrop in the Murray formation at the base of Mount Sharp is indicated on an earlier Mastcam view.”

 

“This view from the Mastcam on NASA’s Curiosity Mars rover shows an example of cross-bedding that results from water passing over a loose bed of sediment. It was taken Nov. 2, 2014, at a target called “Whale Rock” within the “Pahrump Hills” outcrop at the base of Mount Sharp.

This view from the Mast Camera (Mastcam) on NASA’s Mars rover Curiosity shows an example of cross-bedding that results from water passing over a loose bed of sediment.

The cross-bedding — evident as layers at angles to each other — reflects formation and passage of waves of sand, one on top of the other. These are known as ripples, or dunes. The direction of migration of these small ripples and dunes was toward the southeast. That direction is toward Mount Sharp and away from the area where Curiosity found evidence of delta deposits where a stream entered a lake. The directional flows recorded in the sediments are interpreted to have formed by currents moving down the deltas and into deeper lake water.

The color has been approximately white-balanced to resemble how the scene would appear under daytime lighting conditions on Earth. Figure A [pictured above] is a cropped version with a superimposed scale bar of 50 centimeters (about 20 inches) just beneath the cross-bedding.

The Mastcam’s right-eye camera captured the component frames of this mosaic image at a target called “Whale Rock” during the 796th Martian day, or sol, of the rover’s work on Mars (Nov. 2, 2014). The location of Whale Rock within the “Pahrump Hills” outcrop at the base of Mount Sharp is indicated on an earlier Mastcam view .”

These are but a few of the photographs which are available to view on the Mars Science Laboratory website.  If they have the same impact on you, the you have many happy hours of viewing ahead of you… We can only imagine what Sanjeev and the other scientists felt receiving these images for the first time.

I can also recommend the articles in February’s “Elements” magazine:  February 2015: Mineralogy of Mars  (v.11 issue 1).

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