Earth is the only habitable planet in our solar system. But that might not have always been the case. A study from 2017 points to the possibility of Mars being habitable at one point, close to the time life on Earth began.
Take the Gale Crater for example, where a 90-mile wide hole stands now there used to be a large lake filled with fresh water. The water is long gone sadly, but the sediments that remained paint a story of how Mars was probably habitable in the past, and even hospitable to life.
We can gather this information through the use of the Curiosity rover which has been on Mars since 2012. The rover has been traversing the Gela Crater and the three-mile high Mount Sharp as it studies the layers of rock that once laid at the bottom of this fresh-water lake.
An analysis from 2017 has revealed that the red planet was indeed once capable of supporting life. This was sometime in the period between 3.8 and three billion years ago. The planet contained all the necessary chemical and energetic materials at about the same time that Earth saw its first life forms emerge.
A team of geochemists led by Joel Hurowitz studied the chemical contents from a hundred meters of rock layers located in the Gale Crater. In order to successfully reconstruct the climate from the red planet’s past, the team measured the amount of aluminum found in each of the layers, and they then compared those numbers to the amount of minerals like sodium and calcium.
This was done because water is better at dissolving rocks in warmer conditions. If a layer contains more aluminum that means it was formed under warmer conditions. On the other hand, cold water is not as chemically active, so the layers formed in those conditions contain higher amounts of sodium and calcium.
The analyzed rocks told scientists that the weather on Mars was cool at first, but then at one point it began heating up. With that heat came moisture as well. The layers later indicate that the surface of Mars dried out due to a catastrophic loss of atmosphere which occurred at one point in time. Nevertheless, the study clearly shows that the surface of Mars had a mild climate for a much longer period than previously suspected.
Add to that the fact that the layers of the lake were full of oxidizing agents, while the deeper ones contained reducing agents. The combination of these molecules was enough for Martian life-forms to feed on and thus get energy.
Additionally, the lake had many smaller ecological systems in which even organisms from Earth might have thrived. Some niches contained a lot of oxygens, niches that contained small amounts of oxygen, and there were niches which had all the oxygen levels in between.
This particular lake may have been a hot spot for microbial life. The number of various life-forms the lake could have supported is impressive.
Unfortunately, this is all that the Curiosity rover may reveal when it comes to life on Mars. It is not equipped for answering whether life on Mars ever did evolve. The Curiosity rover gave us the answers to where and when life may have existed on Mars. Now it is up to the Mars 2020 rover to find actual evidence of life on Mars when it finally arrives.
As her name suggests, Jenna Small stands little over 4ft tall. Being petite and blonde, many often underestimate her talent. As a result, she spent her entire life working twice as hard to prove that she was the best. Now an established geologist, she does not beat around the bush when it comes to her work. Her research has been published and used in schools throughout the region. She often states that her most significant accomplishment was choosing to better herself through a solid education. When she is not busy unearthing new findings, she volunteers as a motivational speaker to girls who have been victims of bullying, discrimination, or harassment.