Although Mars seems cold and inhospitable today, it was different 3,000 or 4,000 million years ago. A new study suggests that the Red Planet was once warm enough to house storms of rain and running water, which would have created an environment that could support a simple life.
The certainty that there was water on ancient Mars has been common for years, but its form was in debate. The scientists were not sure if the water was trapped in the ice or if it really flowed over the surface. There was also uncertainty about the duration of the water flow and if the temperatures were warm enough to allow it.
A warm surface with flowing water supports the idea that life could have formed independently on the planet’s surface.
The new study includes a comparison of the patterns of mineral deposits with those of the Earth, which paints an image of one or perhaps several long-term periods of a warm Mars with rain storms and running water. Later, as temperatures dropped, the water would freeze.
Today, the average temperature on Mars is -26.7 degrees Celsius. Between that and the thin atmosphere, Mars has a hostile environment compared to its warmer past.
“Here on Earth, we find silicon deposits in glaciers that are characteristic of melted water,” said Briony Horgan, a professor at Purdue University. “On Mars, we can identify similar silica deposits in younger areas, but we can also see older areas that are similar to the deep soils of hot climates on Earth. This leads us to believe that on Mars 3,000 or 4,000 million years ago, we had a slow general tendency from warm to cold, with periods of defrosting and freezing. If so, it is important in the search for a possible life on Mars. ”
Horgan presented the article at the Goldschmidt Geochemistry Conference this week in Barcelona.
Comparing mineral deposits could shed light on the similarities between ancient Mars and ancient Earth, something that missions to Mars could investigate.
On Earth, weather affects the patterns of how minerals are deposited. The same pattern was observed on Mars.
“We know that the basic components of life on Earth developed very soon after the formation of the Earth, and that flowing water is essential for the development of life,” said Horgan. “Therefore, the evidence that we had water on Mars will increase the chances of a simple life having developed at about the same time as on Earth. We hope that the Mars 2020 mission can observe minerals more closely, and begin to respond exactly what conditions existed when Mars was still young. ”
There are no unmanned missions investigating the oldest rocks on Mars. Data for the study were collected by NASA’s Compact Recognition Imaging Spectrometer for Mars.
“If our findings are correct, then we must continue working on the climate models of Mars, possibly to include some chemical or geological process or another process that could have warmed the young planet,” Horgan said.