A research team led by Thomas Watters of the Smithsonian Institution has found evidence of the existence of a thick sedimentary layer containing ice (water ice) in a region called the Medusae Fossae Formation (MFF) on Mars. We announced the research results that showed that. The maximum thickness of the sedimentary layer is 3.7 km, and it seems possible that there is a large amount of water in the form of ice, enough to cover the entire Mars at a depth of 1.5 to 2.7 m. A paper summarizing the research team’s results has been published in Geophysical Research Letters.
[▲ Diagram showing the location of the Medusae Fossae Formation (MFF) on Mars. MFF is located southwest of Olympus Mons and just south of the Equator. Image colors are colored according to altitude (Credit: ESA)]
According to the European Space Agency (ESA), the MFF is a region formed by wind erosion that is several kilometers high and spreads over hundreds of kilometers across, and is located near the border between lowlands in the Northern Hemisphere and highlands in the Southern Hemisphere. The focus is on its latitude: unlike the North and South poles, which have polar caps of water and carbon dioxide ice, MFF is only a few degrees south of the equator. Although it was known that there was a sedimentary layer in MFF, it was not known what it was made of, and it was thought that volcanic ash or dust may have been deposited there.
[▲ Diagram showing the distribution and estimated thickness of the sedimentary layer containing ice (water ice) believed to be buried near the equator of Mars (assuming the thickness of the material covering the sedimentary layer is estimated to be 300 m) ). It can be seen that the maximum thickness of the sedimentary layer is nearly 3 km (Credit: Planetary Science Institute/Smithsonian Institution)]
Watters, who also led the research team that reported the discovery of the MFF sediment layer in 2007, used the underground exploration radar altimeter “MARSIS” aboard ESA’s Mars Express rover “Mars Express.” I have been observing MFF.
Initially, the maximum thickness of the sedimentary layer was estimated from MARSIS data to be 2.5 km, but the latest observations have revealed that the maximum thickness is 3.7 km, which is comparable to the maximum thickness of the southern polar cap layered deposit (SPLD). became. In addition, the latest data shows that the deposits are relatively transparent to radar waves and have a low density, and that the ice is deposited in layers, similar to the polar caps.
[▲Diagramshowingtheobservationrange(topwhiteline)andobservationdata(bottom)byMarsExpress’MARSISThetwomassifswhosesurfacesarecoveredwithdrymaterial(dustorvolcanicash)maybefilledwithice(waterice)(Credit:CReSIS/KU/SmithsonianInstitution)
Using new observations and a sediment model, the research team found that if only volcanic ash and dust were deposited, they would be compressed under their own weight, which explains both the thickness and low density of the actually observed sediment layers. It turns out that it can’t be done. The research team believes that the MFF’s sedimentary layer consists of a thick layer of ice-containing dust, covered by a layer of dry material (dust or volcanic ash) at a depth of 300 to 600 meters.
According to the Smithsonian Institution, the amount of water stored as ice in the MFF is up to 50% of the polar cap layered deposits (NPLD), far more than the total water volume of the Great Lakes in North America, and extends 1.5 to 2.7 meters above the surface of Mars. It is estimated that the amount is sufficient to cover the area at a depth of . When Mars’ ice-containing sedimentary layers were left behind in the MFF, the tilt of Mars’ axis of rotation was different from what it is now, and it is thought that the region near the equator was colder than it is today, and the polar regions were warmer.
Related article: Climate simulation reveals that liquid water may have flowed on Mars “very recently” (July 10, 2023)
[▲ Cross-sectional view of the presumed Medusae Fossae Formation (MFF). The image below shows the estimated underground structure in the white line area of the image above (roughly north-northwest to south-southeast). Beneath the surface (red) is a layer of dry material (orange), and below that is thought to be a thick layer of sediment containing water ice (blue). (Credit: CReSIS/KU/Smithsonian Institution )]
Water ice, which is believed to be buried underground on Mars, is attracting attention from various perspectives. Water is one of the essential materials for human survival and life, and hydrogen and oxygen obtained through electrolysis can be used as propellants for rocket engines, so future manned Mars exploration will mine ice on site. This is also being considered. The excavated ice could also provide information about the ancient Martian climate, as well as evidence of past (and in some cases, present) life.
For these reasons, MFF has the potential to become one of the areas of particular interest in Mars exploration. The MFF’s location close to the equator requires relatively little energy to maintain its temperature, and its relatively low altitude makes it easier to use the atmosphere to slow down spacecraft and landers. Masu. The large amount of reserves will attract attention in projects such as Mars colonization promoted by SpaceX CEO Elon Musk. The discovery of ice that may be hidden beneath hundreds of meters of dust could have a major impact on the future of Mars exploration.
Source
- ESA – Buried water ice at Mars’s equator?
- Smithsonian Institution – New Study Reveals Evidence of an Ice-Rich Layered Deposit on Mars
- Watters et al. – Evidence of Ice‐Rich Layered Deposits in the Medusae Fossae Formation of Mars (Geophysical Research Letters)
Text/sorae editorial department
