People of Northwest Public Radio
Thu February 6, 2014
NASA Probe Finds Newly Formed Crater On Mars
Originally published on Thu February 6, 2014 4:42 pm
Take a close look at the stunning image above showing a newly formed impact crater on Mars: The blue streaks of material, known as ejecta, radiate 9 miles from the 100-foot crater, according to NASA.
The picture was taken from orbit by the Mars Reconnaissance Orbiter on Nov. 19. The same area was imaged by the MRO's Context Camera in July 2010 and again in May 2012 — with no crater in the first and a telltale surface scar in the second.
The orbiter's HiRISE camera was used on the latest pass to get more details, according to the University of Arizona, Tucson, which runs the instrument:
"Our image shows a large, rayed blast zone and far-flung secondary material around an approximately 30 meter-diameter (100-foot) crater indicating a large explosion threw debris as far as 15 kilometers (9.3 miles) in distance. Because the terrain where the crater formed is dusty, the fresh crater appears blue in the enhanced color due to the lack of reddish dust."
NASA has run before-and-after imaging of fresh craters on Mars before and has determined that there are about 200 new ones per year of at least 12.8 feet in diameter. However, the space agency says, "few of the scars are as dramatic in appearance as this one."
As many people know, NASA commonly uses what is known as "false color" to enhance certain features on what otherwise are often black-and-white images from the Hubble Space Telescope, as well as various planetary probes, including the Mars orbiter. What fewer people might know is that the practice is somewhat controversial.
Io9.com reports there was "a minor furor" in 2004 when a New Scientist article raised questions about the true color of Mars, saying there were "accusations of NASA tinting the pictures it got from Mars to make it look more like the Red Planet of legend."
According to io9:
"It turned out to be a simple filtering mix up. The Mars rover used green, blue, and red filters to approximate colors as people would see them. The red filter, however, was usually a waste of time, since [there] was little green or blue on Mars. There were some on the [spacecraft] that had landed, though, as so when the rover used green, blue, and infrared filters, the blues and the greens looked reddish, and people saw the entire picture as 'fake.' "
And as SPACE.com has pointed out:
"[Throughout] the storied history of the Hubble Space Telescope, the beauty of those color images has sometimes overshadowed one important question: Where does that color come from? After all, some of Hubble's amazing photos — and images from other space telescopes, for that matter — depict astronomical objects in ultraviolet or infrared light. But the human eye can't perceive those colors. When people look at a Hubble image showing these hues, what exactly are they seeing?"
NASA image processor Zolt Levay asked, writing in Sky and Telescope:
"The flat-out gorgeous Hubble spacescapes look too good to be true. Are these objects really so colorful? If we could fly out to these celestial wonders, would they look this way to our eyes? If not, as a few hard-core NASA cynics claim, are the pictures being overly colorized to seduce the public? What is 'truth' when it comes to Hubble's universe?"