New Martian Crater Spotted on Mars (VIDEO)

NASA's Mars Weather Camera has spotted the largest fresh meteor-impact crater ever, spanning half the length of a football field.

First discovered in March 2012, the crater was captured in before-and-after images by NASA's Mars Reconnaissance Orbiter (MRO).

Researchers speculate that the Martian crater was likely formed from a preceding explosion caused by intense friction between an incoming asteroid and the planet's atmosphere. This event is comparable to the meteor that struck Chelyabinsk, Russia, last year. The air dust and the ground impact together made a dark region on the Martian surface stretching about 5 miles (8 kilometers) across.

The MRO has been conducting systematic observations of Mars since 2006, searching for clues of dust storms and other weather patterns via its weather-monitoring camera, the Mars Color Imager (MARCI).

Then, two months ago scientist Bruce Cantor noticed a dark spot near the Mars equator.

"It wasn't what I was looking for," Cantor said in a statement. "I was doing my usual weather monitoring and something caught my eye. It looked usual, with rays emanating from a central spot."

To verify the discovery, Cantor examined previous images taken by MARCI, which revealed that the dark spot was present a year ago, but not five years ago. Further exploration from about 40 different dates finally let Cantor pin down the exact date of the impact event: March 28, 2012.

Out of all the other 400 fresh crater-causing impacts found on Mars, this newest, inconspicuous dot is the first to be documented using MARCI imaging.

In 2012, the site of the new crater was scanned and photographed by telescopic Context Camera (CTX). In April 2014 CTX images, two craters were spotted that were not there earlier, thus confirming that the dark spot located by MARCI was a fresh crater.

"Studies of fresh impact craters on Mars yield valuable information about impact rates and about subsurface material exposed by the excavations," said Leslie Tamppari, deputy project scientist for the MRO mission at NASA's Jet Propulsion Laboratory in Pasadena, Cali. "The combination of HiRISE and CTX has found and examined many of them, and now MARCI's daily coverage has given great precision about when a significant impact occurred."