An impact crater measuring half the length of a football field has been discovered on Mars. This is the largest fresh impact crater in our Solar System ever confirmed with before-and-after images.
NASA's Mars Reconnaissance Orbiter captured the images of the Red Planet documenting the crater, which first appeared in March 2012, but went unnoticed. It was only about two months ago that scientist Bruce Cantor happened to notice 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."
Cantor began examining earlier images, noting that the dark spot was present a year ago, but not five years ago. After scanning through images from about 40 different dates, he narrowed the time of impact down to March 27-28, 2012. Scientists then aimed high resolution cameras at the spot, revealing the crater, which was described as "unusual" and "quite shallow compared to other fresh craters we have observed" by Principal Investigator Alfred McEwen of the University of Arizona, Tucson.
The crater is slightly elongated and spans 159 by 143 feet. McEwen estimates the impact object measured about 10 to 18 feet long. The darkening in the original image is likely attributed to a number of landslides in the area, which were possibly triggered by a shockwave caused by the explosion in the atmosphere or the ground impact.
Because Mars' atmosphere is significantly thinner than Earth's, meteorites are more likely to make it to the Red Planet's surface and cause larger craters. Does that Mars One colonization mission sound any less inviting, now?