After an experiment conducted on Earth microbes that were taken out of permafrost and put into an environment that is a replica of the Martian atmosphere; some of the microbes had survived the exposure to very low oxygen levels and the cold. This means that there could be simple lifeforms on Mars. In the future we might send astronauts to Mars and eventually we would want to terraform Mars to put a small population of colonists on the red planet and it would be good to be able to find martian life on the planet. Terraforming the Martian environment could be carried out by introducing some form of lichen that would take in carbon dioxide and put out oxygen. This would be a very slow process but the change in the atmosphere would then allow us to plant some trees and further change the atmosphere to eventually make it breathable at low altitudes. We would need a very powerful spacecraft to make it to Mars quickly enough; but that will be a possibility in the future. The Prometheus movie put forward the idea that life on our planet was introduced by a technologically advanced race a long time ago. It is also possible that life was spread by comets, which do carry organic material. That is why the possible lifeforms were found in a meteorite that originated from Mars.
There is nothing wrong with the idea of life on other planets. The Universe is 500 billion light years across, or 930 Yottameters. This is an astonishing distance, we are not necessarily at the center of the Universe but it is amazing to think that the Universe is that big. This means that there are countless galaxies in this massive space and they could contain many, many inhabited planets with beings on them that are looking up into space with their own telescopes and wondering the same thing. Are they looking in our direction from however far away and wondering if our galaxy has lifeforms just like them? That is why we need to study the Martian environment; if we can determine conclusively that life exists on Mars, then we can start looking further afield for other signs of extraterrestrial life. There are many extremophiles that survive on Earth in pools of concentrated acid and superheated water under the ocean near black smoker volcanic vents. The same lifeforms could be living on the Jovian moon Europa. Since it has a massive ocean under the thick ice; it is possible that life exists on this moon in the dark deep ocean. Mars could have life that exists deep under the surface in caves and lava tubes that is safe from the harmful solar radiation that makes the surface unlivable.
Europa would be beset by the same problem; there is practically no atmosphere, but what atmosphere there is contains mostly oxygen. Life would only exist at the bottom of the ocean though and not on the surface. If there is geothermal heating on Europa and volcanic vents at the bottom of the ocean then life could easily exist in this environment. Not life that we could communicate with, but simple lifeforms that would thrive in the warm and nutrient rich environment. The water coming out of a black smoker can be up to 464 degrees Celsius, this temperature does not stop life from existing here though. The NASA Opportunity rover has discovered a type of clay soil that only exists around water with a neutral acidity. This is a good indication that life could have existed on Mars a long time ago. The planet Mars could have been a very nice place to live long ago; but now it is an inhospitable and cold place that cannot support complex lifeforms. Something could live underground but not on the surface. Hopefully we will send humans to this planet to investigate the surface further; that is the only way that we will learn more about our next door neighbor. There are many sights in our Universe that we are missing if we stay on our lonely little planet and we do not extend our reach with manned missions to other planets and eventually to the stars.