Q-news
CITE
We have made every effort to follow citation style rules, but there may be some minor differences. If in doubt, please refer to the appropriate citation style manual.
Evidence of flowing water discovered on Mars. (2022). In Q-files Encyclopedia, , Q-news. Retrieved from
https://www.q-files.com/news/evidence-of-flowing-water-discovered-on-mars
"Evidence of flowing water discovered on Mars." , Q-news, Q-files Encyclopedia, 10 Feb. 2022.
https://www.q-files.com/news/evidence-of-flowing-water-discovered-on-mars.
Accessed 19 Mar. 2024.
Evidence of flowing water discovered on Mars 2022. , Q-news. Retrieved 19 March 2024, from
https://www.q-files.com/news/evidence-of-flowing-water-discovered-on-mars
, Q-news, s.v. "Evidence of flowing water discovered on Mars," accessed March 19, 2024.
https://www.q-files.com/news/evidence-of-flowing-water-discovered-on-mars
Evidence of flowing water discovered on Mars
Images taken from the Mars Reconnaissance Orbiter, a space probe in orbit around Mars, show long, dark streaks on the steep walls of the Red Planet's valleys and craters in the summer months of the Martian year. Some stretch downhill for hundreds of metres before they dry up in the autumn, when temperatures drop. In places, the streaks combine to form fan-like patterns. Researchers say the streaks are clear evidence of liquid water running down canyon and crater walls. This discovery raises the chances of Mars being home to some form of life. “Mars is not the dry, arid planet that we thought of in the past,” said NASA’s Jim Green. “Liquid water has been found on Mars.” The water flows on Mars could indicate the most promising sites to find life on Mars. These would then be key possible landing sites for any future human missions to Mars, as vital water supplies for the astronauts could be collected from natural sources.
Scientists have long suspected Mars has had liquid water on its surface in the past. Pictures beamed back to Earth from the Viking space probes that landed on Mars in the 1970s showed what looked like dried-up beds of ancient rivers and lakes. There are many valleys and channels that look as if they were carved by running water. The presence of sediments (muds and silts deposited in water) makes this even more likely to have been the case. NASA has since found evidence of an ocean that might have once covered much of the planet’s northern hemisphere millions of years ago.
Mars space probes have also recently found evidence that the planet might still have liquid water (frozen water—ice—has long been known to exist on the Martian surface). Orbiting craft have sent back images of what appears to be water flowing down gullies and crater walls in the summer months. Mission scientists have named these flows: recurring slope lineae (RSL).
Instruments on board the Mars Reconnaissance Orbiter have now analysed the chemical make-up of the RSL flows. Using a spectrometer to look at infrared radiation reflected off the steep rocky walls where the dark streaks appear, scientists have discovered the presence of salts in the streaks—a key indicator for the presence of water. The same observations were made at four different sites: Coprates Chasma canyon, and the Hale, Palikir and Horowitz craters. The flows only appear when the surface temperature of Mars rises above -23?C, but the water does not freeze because the salts dissolved in it lower the freezing point of water.
Scientists do not know for sure where the water comes from originally. One theory is that it may be the meltwater from ice held in porous rocks lying just beneath the Martian surface and which rises to the surface in the warmer summer months. Alternatively, the liquid may condense out of water vapour in the thin Martian atmosphere. Salts on the ground may absorb water from the atmosphere until there is enough for the liquid to start running downhill. This process occurs in the Atacama Desert in Chile, one of the driest places on Earth—microbes are known to live in the resulting damp patches found in this otherwise arid landscape.