Humanity is curious – how come the Earth is the only planet in the Solar system that harbours life? What is so special about Earth that allowed it to develop atmosphere and a suitable climate? Maybe it wasn‘t always like that? Scientists already know that ancient Mars had liquid water and now they are speculating that rocks near ancient lake sites could be hiding signs that once there was life on the Red planet.
Humans are very good at looking for signs of ancient life – we’ve been doing it for a very long time on our own planet. And so it is about time to turn our attention to palaeontology in Mars. Scientists think that the best place to look for fossil evidence about extinct life on Mars is some rocks situated where lakes used to be. Scientists have been thinking that Mars could have supported primitive life forms around four billion years ago. It probably was microbes but the evidence of them would still be hiding somewhere between these old rocks.
How scientists know where to find these signs of ancient life forms? Well, a team of scientists led by The University of Edinburgh determined that the best place to look for fossil records of Mars’ microbes is sedimentary rocks made of compacted mud or clay. These rocks are not entirely different from what we have on Earth – they contain large amounts of iron and silica, which is known to preserve fossils. These rocks formed 3-4 billion years ago during Noachian and Hesperian Periods of Martian history, when the planet was rich with water. We have very similar rocks with fossils on Earth too, but they are not as good condition like the Mars ones. It is because Mars doesn’t have plate tectonics, which can crush surface rocks.
Humans don’t have a lot of time on Mars to keep looking for fossils. That is why scientists replicated Marsian conditions in a laboratory to figure out the best spots to find these promising rocks. And the time is pretty much perfect – NASA is planning to send a robot to Mars in 2020. It should return some rocks back to Earth. A similar mission is planned by the European Space Agency as well. Dr Sean McMahon, one of the authors of the study, said: “There are many interesting rock and mineral outcrops on Mars where we would like to search for fossils, but since we can’t send rovers to all of them we have tried to prioritise the most promising deposits based on the best available information”.
We are hoping to expand our knowledge about the universe and neighbouring planets. It seems like the Mars is the number 1 target right now. National and private space agencies are keeping their eyes on the Red planet and hopefully we will make huge discoveries in the coming decade.
Source: The University of Edinburgh