We know Mars was once much wetter than it is now, but it is much more challenging to answer when water formed and evaporated away.
A new study now suggests that the Red Planet had water some 4.4 billion years ago - much earlier than previously thought.
Based on an analysis of NWA 7533, experts picked up a meteorite in the Sahara Desert. They thought the said meteorite originated billions of years ago on Mars. The oxidation within the meteorite of certain minerals hints at the presence of water.
The findings could push back some 700 million years from the estimated date of water formation on Mars, from the 3.7 billion-year timeframe that has been the consensus until now. The research could also give some insights into how, in the first place, planets form.
"This is the first time I have investigated this particular meteorite, nicknamed 'Black Beauty' for its dark color," said a planetary scientist Takashi Mikouchi from the University of Tokyo, Japan.
Experts used four different types of spectroscopic analyses to detect chemical fingerprints in our NWA 7533 samples. The findings have led our team to draw some interesting conclusions.
The tale of water on planets and moons is of great interest to planetary scientists. One of the big unknowns is whether water is added to a planetary body after it forms, through the effects of asteroids and comets, or whether it occurs naturally during the process of planet formation.
How can a meteorite tell time?
Ancient rocks such as NWA 7533 can help researchers peer back in time and find out as they record impact events on the planet from which they come and capture some of the surface's mineral and chemical composition when created.
In this case, the tell-tale sign of water is oxidation. It's the oldest record we have of Mars with specific fragments within NWA 7533 dated to 4.4 billion years ago (which may be why a single gram of this meteorite can get as much as US$ 10,000).
"Igneous clasps, or fragmented rock, are formed from magma in the meteorite and are generally caused by impacts and oxidation," says Mikouchi. "This oxidation could have occurred 4.4 billion years ago during an impact that melted part of the crust if there was water present on or in the Martian crust."
Such an early appearance indicates that when Mars was formed, water was around and that in turn, plays in public research into planetary formation. With water comes life, one reason why scientists are so inclined to monitor it around the solar system. By comparison, we know that the earliest marks of life on Earth date to at least 3.5 billion years ago.
Further studies
As experts try to figure out when water was present and what form it could have taken, the close study of Mars continues. A recent study put forward the idea that both liquid water and surface ice could have existed simultaneously on the Red Planet.
The team results also suggest that the Martian atmosphere's chemical makeup at this time, including high levels of hydrogen, could have made the planet warm enough for water to melt and life to exist, even though during this period, the Sun would have been younger and weaker.
Mikouchi said their analysis suggests that such an impact would have released a lot of hydrogen. According to him, the phenomenon would have contributed to planetary warming when Mars already had a carbon dioxide thick insulating atmosphere.
