When the discovery of what appeared to be microbial fossils in a martian meteorite was announced in 1996, it was an exciting development that triggered investment in Mars research.
Scientists now think that life evolved on Mars, and might be still living there. But it’s a long shot that we will ever be able to find evidence of life on the Red Planet.
1. Water
Mars may not have liquid water today, but a new study suggests it could have in the past. Scientists analyzing data from the European Space Agency’s Mars Express orbiter found evidence that a large lake may be beneath the south Martian pole.
In a paper published in Nature Astronomy, the researchers used computer modeling to explore the possibility of a lake that’s kept warm by geothermal heating. The team plugged in variables like the depth of the lake, friction caused by the weight of the ice beneath it, and the amount of geothermal heat generated under Mars in recent history.
2. Atmosphere
Mars is surrounded by dust and ice, but it also has a thin atmosphere. Thin wispy clouds can form in the upper layers of the atmosphere and around mountain peaks.
This makes it a difficult place for life to develop and thrive, but there is some hope. Scientists have a new model for early Mars that suggests it may have had a thicker atmosphere and could have been habitable to methanogenic microbes, which produce methane.
The model estimates that early Mars had a gaseous atmosphere with a pressure 1.2 percent of Earth’s total atmospheric pressure, which would allow liquid water to exist. That would require a lot of CO2 to make the planet warm enough for liquid water, which could be introduced into the atmosphere by sending vaporized polar ice caps onto the Martian surface or by diverting comets toward Mars.
3. Temperature
While Mars might look like a tropical desert, it’s actually extremely cold. The Red Planet is more than 50 million miles from the Sun, which means it gets very little heat to keep it warm.
If you were to stand on the surface of Mars, it would be cold enough for plants and animals to freeze instantly.
This is because it’s so far away from the sun that it lacks a “thermal blanket” to keep it warm.
To make life possible on Mars, scientists need to create a thermal environment that is similar to the one found on Earth. This can be done by creating an atmosphere that retains heat.
4. Minerals
Minerals are substances with distinctive chemical and physical properties, composition and atomic structure. They are found in nature and are used for many purposes including food, drinking water, and building.
The different characteristics of minerals are important to understand. These include how transparent or opaque they are, and how they break along flat surfaces (called cleavage).
In addition to their physical characteristics, minerals can be identified by the elements that they contain. These include carbon, oxygen, hydrogen, nitrogen and phosphorus.
5. Light
Light is the most powerful energy source in nature. It allows life to exist and thrive on a global scale.
It enables Earth-based organisms to move across the solar system, and it is responsible for photosynthesis on Earth. It is also a vital element in the production of energy, such as the movement of the sun around our planet.
On Mars, life would require a different kind of energy source. Since geothermally derived chemical energy is very limited, it would be unlikely to power the formation of a biosphere on this world.