Margaritifer Sinus Quadrangle - Mars Science Laboratory

Mars Science Laboratory

Several sites in the Margaritifer Sinus quadrangle have been proposed as areas to send NASA's next major Mars rover, the Mars Science Laboratory. Both Holden Crater and Eberswalde Crater made the cut to be among the top four. Miyamoto Crater was in the top 7 sites chosen. Holden Crater is believed to have once been a lake. Actually, it is now believed that it held two lakes. The first was longer lived and was formed from drainage within the crater and precipitation. The last lake began when water damed up in Uzboi Vallis broke through a divide, then rapidly drained into Holden Crater. Because there are rocks meters in diameter on the crater floor, it is thought it was a powerful flood when water flowed into the crater.

• West Rim of Holden Crater, as seen by THEMIS. Click on image to see more details.

• Close-up of Channels on Rim of Holden Crater, as seen by THEMIS. Click on image to see more details.

Eberswalde Crater contains a delta. There is a great deal of evidence that Miyamoto Crater once contained rivers and lakes. Many minerals, such as clays, chlorides, sulfates, and iron oxides, have been discovered there. These minerals are often formed in water. A picture below shows an inverted channel in Miyamoto Crater. Inverted channels formed from accumulated sediments that were cemented by minerals. These channels eroded into the surface, then the whole area was covered over with sediments. When the sediments were later eroded away, the place where the river channel existed remained because the hardened material that was deposited in the channel was resistant to erosion. Iani Chaos, pictured below, was among the top 33 landing sites. Deposits of hematite and gypsum have been found there. Those minerals are usually formed in connection with water.

• Iani Chaos, as seen by THEMIS. Sand from eroding mesas is covering brighter floor material. Click on image to see relationship of Iani Chaos to other local features.

• Landing zone in Iani Chaos, as seen by THEMIS.

The aim of the Mars Science Laboratory is to search for signs of ancient life. It is hoped that a later mission could then return samples from sites that the Mars Science Laboratory identified as probably containing remains of life. To safely bring the craft down, a 12 mile wide, smooth, flat circle is needed. Geologists hope to examine places where water once ponded. They would like to examine sediment layers.