Earth & Environmental Sciences Blogs

  Figure 1 Perspective view of crater with water ice at Martian north pole. Due to the low atmospheric pressure on Mars' surface, liquid water can only exist at the lowest elevations for short periods of time. Water appears to make up the majority of the two polar ice caps. If the water ice in the south polar ice cap were to melt, it would cover the entire planet's surface to a depth of 11 meters. The permafrost mantle reaches from the pole to around 60 ° latitude. Large amounts of water ice are believed to be trapped within Mars' thick cryosphere. Radar images from Mars Express and the Mars Reconnaissance Orbiter reveal huge amounts of water ice at both the poles and mid-latitudes from July 2005 to November 2008. On July 31, 2008, the Phoenix lander took a direct sample of water ice in shallow Martian soil. Figure 2  The north pole of Mars at the summer solstice, as seen in an image shot by the European Space Agency's Mars Express in May 2010. Landforms visible on Ma...

  Figure 1 Famous micrograph of Mars meteorite ALH84001 shows structures that resemble fossils, but most scientists regard them as mineral formations. Perseverance seeks less ambiguous evidence. NASA/JSC Allan Hills 84001 (often abbreviated ALH84001) is a meteorite discovered by a team of US meteorite hunters from the ANSMET project on December 27, 1984, in Allan Hills, Antarctica. ALH84001, like the other SNCs (shergottite, nakhlite, and chassignite), is assumed to be from Mars. It does not, however, fit into any of the previously identified SNC groupings. It weighed 1.93 kilos when discovered (4.3 lb). It made headlines throughout the world in 1996 when scientists stated that carbonate globules found there might include evidence for minuscule remains of Martian microorganisms. This rock is thought to be one of the Solar System's oldest parts, having crystallized from molten rock 4.091 billion years ago. It is considered to have evolved on Mars during a period when liquid w...