The great success of the arrival of the Mars Rover Curiosity on the Red Planet has made us forget that for about eight Earth years and a half on Mars there’s the Mars Rover Opportunity which keeps on working and last May went back in activity after spending the Martian winter in a sort of hibernation. Now, Opportunity is in the segment called Cape York, in northern area of the Endeavour crater, where it photographed odd speres in the ground.
In 2004, the Mars Rover Opportunity had already discovered spherules in its landing area that were nicknamed “blueberries”. Later, spherules of the same kind were found in other places and they were iron-rich formations originated by the precipitation of minerals out of the water that become rigid masses in sedimentary rocks. The ones found a few days ago in the Cape York outcrop called Kirkwood are different.
At first glance, these spherules that have a diameter of up to three millimeters (about a tenth of an inch) don’t look like much, instead Steve Squyres, the mission Opportunity’s principal investigator, defined their picture, a mosaic obtained by combining four images taken by the instrument Microscopic Imager (MI), one of the most extraordinary of the entire mission.
[ad name=”AmazonDocumentary”]
Kirkwood is full of those tiny spheres and initially scientists thought that they were more “blueberries”. However, the preliminary analysis made by the Mars Rover Opportunity shows that these spheres don’t have the high iron content typical of the “blueberries”. They’re also different concerning their concentration, distribution and structure. Many of the spheres found in Kirkwood are broken and eroded by wind and in cases of partial erosion a concentric structure is evident.
For now, there are several hypotheses on this geological mystery and inevitably it will take time to analyze all the data and try to understand how those spheres formed. Meanwhile, the Mars Rover Opportunity will keep on exploring the Cape York area and at the mission control center they’re optimistic because Opportunity’s energy levels are good. Spring equinox is approaching so the solar energy available will increase over the next few months. Don’t be surprised if new discoveries arrive.
