Aug 02, 2021 07:00:00

It turns out that the 'liquid water' that seemed to exist underground on Mars was actually clay

Since Mars is the closest planet to the Earth's environment, many studies and surveys have been conducted on the possibility of extraterrestrial life.

Among such studies, the research report published in 2020 stating that 'there are many lakes beneath Mars' has attracted a great deal of attention as it enhances the possibility of discovering life on Mars. However, subsequent research has raised the possibility that it is not 'liquid water' but 'frozen clay' that exists beneath Mars.

A Solid Interpretation of Bright Radar Reflectors Under the Mars South Polar Ice --Smith --2021 --Geophysical Research Letters --Wiley Online Library
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021GL093618

Characteristics of the Basal Interface of the Martian South Polar Layered Deposits --Khuller --2021 --Geophysical Research Letters --Wiley Online Library
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2021GL093631

Clays, not water, are likely source of Mars'lakes'
https://phys.org/news/2021-07-clays-source-mars-lakes.html

A study published in 2020, based on radar-measured data from the Mars probe Mars Express, 'discovered the existence of many lakes filled with large amounts of saltwater beneath Mars.' Was to insist.

It turns out that there are several saltwater lakes underground on Mars, increasing the possibility of discovering life --GIGAZINE

However, when Isaac Smith, who studies space at the University of York, re-analyzed the measurement data by Mars Express, the measurement result that 'liquid water exists' remains even at low temperature points where liquid water can not exist. It turned out that 'Given the facts currently known about Mars, liquid water needs to be hotter at the point where the lake is supposed to be,' Smith said. It claims that it may have reacted to substances other than.

A research team led by Smith hypothesized that the substance that the Mars Express radar reacted to was ' smectite,' a type of clay that is abundant on Mars. Then, when the research team actually soaked smectite cooled to minus 45 degrees with water and made it recognized by the radar, measurement results indicating 'liquid water' were obtained.

In addition, when the research team analyzed the data measured around the South Pole of Mars, it became clear that a large amount of smectite exists around the South Pole of Mars. 'These clays have been on Mars since ancient times when there was a lot of water on Mars,' Smith said, speculating that Smectite inhaled liquid water long ago and then froze. I am.

'Other types of clay found on Mars are thought to respond to radar as well as smectite, and I think we've continued to study those clays,' Smith said. I am.