A new study casts doubt on the idea that Mars was once covered in high seas and teeming with life.
A research team has concluded a cold and icy early Mars billions of years ago better explain the observed water drainage and erosion features, the American Geophysical Union reported. The conclusions disputed popular theories suggesting Mars was once Earth-like and had a northern sea.
The make their findings, a team of researchers used a 3-dimensional atmospheric circulation model that compared the water cycle on Mars under different scenarios occurring between three and four billion years ago. Based on the Sun's correlation with Mar's tilt, a cold and icy Red Planet with temperatures of negative 54 degrees Fahrenheit seemed to make the most sense. The cold model also better explained water erosion features that have been observed on the Martian surface.
Mars only gets 43 percent of the solar energy that Earth does, and the Sun that lit early Mars is believed to have been 25 percent weaker that it is today; making it likely Mars was cold billions of years ago. An extreme tilt of the Martian axis would have pointed the planet's poles towards the Sun, moving polar ice towards the equator and creating surface features that can still be seen today. Under the thicker atmosphere that lines up with the colder scenario, highland regions at the equator would have gotten colder and lower-lying areas would have gotten warmer, causing the "icy -highlands" effect that causes the snow on Earthly mountain peaks.
"I'm still trying to keep an open mind about this," said researcher Robin Wordsworth of the Harvard Paulson School of Engineering and Applied Sciences. "There is lots of work to be done. But our results show that the cold/icy scenario matches the surface distribution of erosion features more closely. This strongly suggests that early Mars was generally cold, and water was supplied to the highland regions as snow, not as rain."
The findings were published in a recent edition of the Journal of Geophysical Research - Planets.
