Online Cortex Thoughts on Science and Technology

The Mars Reconnaissance Orbiter (MRO) captured for the first time ever an avalanche in progress on another world! 

These images were taken with the Hi Resolution Imaging Experiment (HiRISE) flying on the MRO.  This image was taken at 34° latitude and 235.8° longitude, which is in Mars’ north polar region. The geology of this region is that of a layered dome of material, and this cliff is located at the edge of it. The cliff is about one half of a mile high! (70 m = 2300 ft) and is incredibly steep with slopes as great as 60°.  The cloud of dust is about 590 feet across and extends about 625 feet from the base of the cliff.

This image was taken on February 18, 2008 at 1:05pm Martian local time. In the northern hemisphere of Mars, spring began on December 10, 2007, and the Carbon Dioxide ice (seen in the left side of the image at the top of the cliff) is beginning to thaw in the spring “heat”.  The Carbon Dioxide ice does not melt, instead it sublimes (turning from a solid to a gas).   As it does sediments and ice in these steep cliffs give way to avalanches. 

The scientists have been watching these particular locations with the hope of catching one in action.  They have succeeded!

Here you can compare before (PSP_007140_2640) and after (PSP_007338_2640) photos.

Kevin Knuth
Albany NY

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Posted under Astronomy, Exploration, Mars, Space

There is now a 4 percent chance that the large asteriod 2007 WD5 may collide with the planet Mars in January 2008.  While there is a 96% chance that the asteriod will miss, these odds are much larger than usual for large asteriod impacts.  If the impact is to occur, it will be on 2008 January 30 at 10:56 UT (2:56 a.m. PST) +- a few minutes.

If this asteriod were heading toward Earth, we would be worried.  The fact that it may hit Mars provides a potential scientific opportunity to monitor a large impact on a terrestrial world from the several space probes currently orbiting Mars, or from the ground-based rovers.  The event would be comparable to the impact of Comet Shoemaker-Levy 9 on Jupiter in July 1994.

The asteriod, which was discovered on November 20, 2007 by the NASA-funded Catalina Sky Survey, recently passed the Earth at a distance of 5 million miles and is currently heading toward Mars at a speed of 27,900 miles per hour.  If a collision were to occur, it will produce a crater similar in size to Barringer Meteor Crater in Arizona with a blast of about 10-15 megatons of TNT, which is similar to the Tunguska Airburst in 1908.

The Near-Earth Object Program at NASA’s Jet Propulsion Laboratory monitors the orbits of known large near-Earth asteroids.  Here are two of their articles on this potential collision.

http://neo.jpl.nasa.gov/news/news153.html
http://neo.jpl.nasa.gov/news/news151.html

Kevin Knuth
Albany NY

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Posted under Astronomy, Mars, Research, Space

While much of Mars looks like the deserts of Utah, the Martian South Polar regions have revealed some surprising geology unlike anything we have here on Earth.

At the 2007 American Geophysical Union Fall Meeting in San Francisco, Chris Okubo, Candace Hansen, and Timothy Titus who work with the Mars Reconnaissance Orbiter’s High Resolution Imaging Camera presented research suggesting that these intriguing structures are caused by explosions of subliming carbon dioxide.

The theory is that there is a layer of translucent Carbon Dioxide ice and when the surface is heated during the summer months, the ground beneath the ice heats up vaporizing the Carbon Dioxide gas.  This gas flows uphill and bursts out of weak spots in the ice.  This results in geysers which spew Carbon Dioxide gas and Martian dust into the atmosphere.  The gas refreezes and snows out forming the white material along the spider-shaped network of tunnels blown out by the subliming Carbon Dioxide.

This same process is believed to be responsible for similar more extensive landscapes called lacework and lizard skin.  It would be fascinating to see these from the ground.

Kevin Knuth
Albany NY 

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Posted under Astronomy, Exploration, Mars, Space

I had been playing with Celestia, and I used it to generate a set of images of Mars as it rotates on its axis.  I then was able to paste these together in Adobe ImageReady to create a rotating Mars gif animation.

Feel free to copy it and enjoy!

Kevin Knuth
Albany NY

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Posted under Astronomy, Fun, Mars, Space

A global dust storm has developed on Mars enveloping the red planet in a shroud of red dust.  At times up to 99% of the sunlight is blocked out, and NASA scientists fear that the rover’s batteries will not last until the storm subsides.  The Mars rovers, Spirit and Opportunity, have been actively exploring Mars for about three and a half years now.  The missions were expected to last only three months!

The sequence of photos below, taken by Opportunity, shows the darkening skies due to the onset of the dust storm over the last month, from Sol 1205 through 1235.  A more detailed picture can be found on Astronomy Picture of the Day.  

To see the extent and severity of this global storm, check out this time lapse movie of Mars’ surface over the last month.  Note that the surface features all but disappear.  Mars’ global storms can last many weeks, and it is unclear whether the rovers can hold out.

Kevin Knuth
Albany NY

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Posted under Astronomy, Exploration, Mars, Robotics, Space