We know that Mars was once much wetter than it is now, but questions about when water formed and evaporated are much more difficult to answer.
New research suggests that water was present on the Red Planet around 4.4 billion years ago, much earlier than previously thought.
The study is based on an analysis of the NWA 7533 meteorite, discovered in the Sahara Desert, and believed to have broken away from Mars billions of years ago. The oxidation of some minerals inside the meteorite indicates the presence of water.
The findings could push back the estimated date for the formation of water on Mars by about 700 million years, compared with 3.7 billion years ago, which was still generally accepted. The study can also provide some insight into how planets form.
“I study minerals in Martian meteorites to understand how Mars was formed, as well as its crust and mantle,” says planetary scientist Takashi Mikochi of the University of Tokyo in Japan.
'This is the first time I investigated this particular meteorite, dubbed' Black Beauty 'for its dark color. Our NWA 7533 samples have been subjected to four different spectroscopic analyzes, chemical fingerprint detection methods. The results have led our team to some interesting conclusions. '
Planetary scientists are very interested in the history of water on planets and moons. One of the unknown moments is whether water enters the planet after its formation as a result of collisions with asteroids and comets, or whether it happens naturally during the planet's formation.
Ancient meteorites like NWA 7533 can help scientists look back in time and figure it out as they record collisions on the planet they happen to and record some of the mineral and chemical compositions of the surface when they form.
In this case, the characteristic feature of water is oxidation. With some fragments inside NWA 7533 dating back 4.4 billion years ago, this is the oldest Mars record we have.
“The igneous debris or rock fragments in a meteorite are formed from magma and usually result from impacts and oxidation,” Mikuchi says. 'This oxidation could have happened if water was present on or in the crust of Mars 4.4 billion years ago during a collision with another cosmic body that melted part of the crust.'
Scientists conclude that water was indeed present in the formation of Mars, and this, in turn, plays a role in studies of planetary formation in general. Life is born with water, and this is one of the reasons why scientists are so eager to find it in the universe. By comparison, we know that the earliest traces of life on Earth date back to at least 3.5 billion years ago.
The team's findings also suggest that the chemical composition of the Martian atmosphere at the time, including high levels of hydrogen, could have made the planet warm enough for water to exist in liquid form and life could exist.
The research is published in the journal Science Advances.
Sources: Photo: Black Beauty Meteorite. (NASA / Luc Labenne)
