You'd need an umbrella made of kryptonite if you were to go walking on Mars apparently.
NASA scientists using images from the space agency's Mars Reconnaissance Orbiter (MRO) have estimated that the planet is bombarded by more than 200 small asteroids or bits of comets per year forming craters at least 12.8 feet (3.9 meters) across.
Using MRO's High Resolution Imaging Science Experiment (HiRISE) camera, NASA researchers spotted 248 new impact sites on parts of the Martian surface in the past decade, using images from the spacecraft to determine when the craters appeared - MRO has been looking at Mars since 2006. The 200-per-year planet wide estimate is a calculation based on the number found in a systematic survey of a portion of the planet, NASA stated.
These asteroids or comet fragments typically are no more than 3 to 6 feet (1 to 2 meters) in diameter. NASA noted that space rocks too small to reach the ground on Earth cause craters on Mars because the Red Planet has a much thinner atmosphere. NASA also added that the meteor over Chelyabinsk, Russia, in February was about 10 times bigger than the objects that dug the fresh Martian craters.
The rate is equivalent to an average of one each year on each area of the Martian surface roughly the size of the U.S. state of Texas. Earlier estimates pegged the cratering rate at three to 10 times more craters per year. They were based on studies of craters on the Moon and the ages of lunar rocks collected during NASA's Apollo missions in the late 1960s and early 1970s.
Counting the rate at which new craters appear serve as researcher's best way to estimate the ages of exposed landscape surfaces on Mars and other worlds.
HiRISE operations are based at The University of Arizona in Tucson. According to the school, the HiRISE camera is the most powerful camera ever to orbit another planet. It has taken thousands of black-and-white images, and hundreds of color images, since it began science operations in 2006. A single HiRISE image will often be a multigigabyte image that measures 20,000 pixels by 50,000 pixels, which includes a 4,000-by-50,000 pixel region in three colors. It can take a computer up to three hours to process such an image.
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