Researchers have discovered on the Red Planet the largest fresh meteor-impact crater ever firmly documented with before-and-after images. The images were captured by
The crater spans half the length of a football field and first appeared in
The darkened spot appears in images taken by the orbiter's weather-monitoring camera, the Mars Color Imager (MARCI). Images of the site from MARCI and from the two telescopic cameras on MRO are at: http://go.usa.gov/8KgJ
Since the orbiter began its systematic observation of Mars in 2006, scientist
About two months ago, Cantor noticed an inconspicuous dark dot near the equator in one of the images.
"It wasn't what I was looking for," Cantor said. "I was doing my usual weather monitoring and something caught my eye. It looked usual, with rays emanating from a central spot."
He began examining earlier images, skipping back a month or more at a time. The images revealed that the dark spot was present a year ago, but not five years ago. He homed in further, checking images from about 40 different dates, and pinned down the date the impact event occurred; the spot was not there up through
Once the dark spot was verified as new, it was targeted last month by CTX and the orbiter's sharpest-sighted camera, the High Resolution Imaging Science Experiment (HiRISE). Of the approximately 400 fresh crater-causing impacts on Mars that have been documented with before-and-after images, this is the only one discovered using a MARCI image, rather than an image from a higher-resolution camera.
CTX has imaged nearly the entire surface of Mars at least once during the orbiter's seven-plus years of observations. It had photographed the site of this newly-discovered crater in
HiRISE reveals more than a dozen smaller craters near the two larger ones seen in the CTX image, possibly created by chunks of the exploding asteroid or secondary impacts of material ejected from the main craters during impact. It also reveals many landslides that darkened slopes in the 5-mile surrounding area. A second HiRISE image in
"The biggest crater is unusual, quite shallow compared to other fresh craters we have observed," said HiRISE Principal Investigator
The largest crater is slightly elongated and spans 159 by 143 feet (48.5 by 43.5 meters).
McEwen estimates the impact object measured about 10 to 18 feet (3 to 5 meters) long, which is less than a third the estimated length of the asteroid that hit Earth's atmosphere near
"Studies of fresh impact craters on Mars yield valuable information about impact rates and about subsurface material exposed by the excavations," said
Astronauts will travel to the asteroid aboard
Malin Space Science Systems,
For more information about the Mars Reconnaissance Orbiter and its findings, visit: http://www.nasa.gov/mro
TNS 30BautistaJude 140523-4744240 30BautistaJude
Most Popular Stories
- National Retail Federation Reduces Sales Forecast
- Pandora Tumbles in Late Trading
- Sporty Ford Fiesta Fires on All 3 Cylinders
- Stop-Start Engines Save Gas, Reduce Emissions
- World Tensions Don't Curb Enthusiasm for Stocks
- Russia Fears Lasting Damage From Ukraine Crisis
- Visa, Amazon Results Drag Down the Street
- U.K. Economy Surpasses Pre-Crisis Peak
- Hispanic Leader Goes the Extra Mile
- Ohio State Band Chief Fired After Probe