Gale (Mars crater)

Mars crater Gale

White borders the landing area of Curiosity in Aeolis Palus , the crater level of the Gale crater ( HRSC data)

position

5 ° 24 ′ S , 137 ° 48 ′ E Coordinates: 5 ° 24 ′ S , 137 ° 48 ′ E

diameter

154 km

history

Age

3.5 - 3.8 billion years

Eponym

Walter Frederick Gale

Oblique view of the crater with excessive elevation

Play media file

Animation of the crater with the planned route of Curiosity (English)

Gale is an impact crater on the planet Mars . Its diameter is about 154 km and its age is estimated to be 3.5 to 3.8 billion years. It should therefore have originated in the Hesperian era . It was named after the Australian astronomer Walter Frederick Gale . The NASA rover Curiosity has been exploring the crater since August 2012 .

Characteristics and location

The crater is located south of the Elysium Planitia Plains , its coordinates are 5.4 ° South and 137.8 ° East. The mountain in the middle of the crater bears the name Aeolis Mons, assigned by the International Astronomical Union (IAU), which is responsible for the Mars nomenclature, and is 5.5 km higher than the actual southern rim of the crater. NASA calls the mountain Mount Sharp after the Californian geologist Robert P. Sharp (1911–2004) and thereby ignores the IAU's nomenclature for the first time.

The history of Gale Crater is long and complex, and reveals different episodes of its history; much of this has not yet been clarified. After the impact that left the Gale Crater, the crater filled with sediment . These were then removed, possibly in a cumulative process. So far, however, it has not been sufficiently clear whether the erosion was caused by water or wind.

A special feature of the Gale crater is the enormous mound of rubble around the central tip of the Aeolis Mons. Dozens, if not hundreds, of different layers deposited over a period of 2 billion years, forming the mound. Each layer thus archives a piece of Mars history. Studies suggest that the current mound was eroded by remains of sedimentary deposits that once filled the entire crater to the right to the crater rim and possibly beyond. However, the nature of the layers is so far largely unknown. One possibility of formation includes both debris that was carried by the wind and volcanic ash that fell from the sky. It is also conceivable that Gale crater once had a lake where the sediments were deposited under the protection of ice.

However, this thesis is scientifically controversial. For most scientists, however, it is possible that water played a crucial role in shaping much of the gale's appeal. If water was ever abundant here, traces of life could also be found on Mars .

The erosion seems to have had a stronger effect in the north and formed a. a kind of alluvial fan . According to some scientists, this could u. a. caused by the deposition of sediments that were transported by water. The shape of these deposits resembles a fan, as usually occurs at the mouth of a canyon or in places where a stream releases its sediments into a stagnant body of water. While the fan of rubble retains some layers, it appears to have been cut by a recently northwest canal. The canal descends over the lower sedimentary layers of the hill towards the northern crater level. High-resolution images from the MOC instrument aboard NASA's Mars Global Surveyor probe suggest that the lower layers have what geologists call a discordance . In addition, a crevice that was formed by erosion during this time would be a break in the geological record.

With the help of the HiRISE camera on board the Mars Reconnaissance Orbiter, stratified rock deposits containing various minerals were detected on the flanks of the Kegelberg . For example, clay minerals were discovered at the foot of the mountain , which could only be formed under the influence of water. According to the spectroscopic measurements of the various Mars orbiters, these sediment layers contain clay minerals and various hydrous sulphates .

exploration

Numerous channels have been eroded into the flanks of the central crater hill and could thus provide access to the layers for further studies. The Gale crater was a possible target for NASA's Mars Exploration Rover Mission in 2003 and one of the four probable landing sites for the ESA ExoMars mission .

On July 22, 2011, it was announced that Gale had been selected as the landing site for the Mars rover Curiosity . The landing took place after about nine months of flight on August 6, 2012 at 5:31 UTC in the Aeolis Palus crater level northwest of the central mountain. It is expected to be able to examine various sediments and rock layers in the crater. Among other things, one should look for possible traces of life. The geological structure of Mars and its climate must also be explored in more detail. This mission is also expected to provide new knowledge in preparation for future manned landings on Mars.