Iron-rich rocks near ancient lake sites on Mars could hold vital clues that show life once existed there, researchers have revealed.
These rocks – which formed in lake beds – could be our best bet for finding traces of life from billions of years ago.
They are rich in iron and a mineral called silica, which helps preserve fossils, and researcher believe they could contain fossils of primitive life from four billion years ago.
Iron-rich rocks near ancient lake sites on Mars could hold vital clues that show life once existed there, research suggests. Pictured, the Jezero Crater delta, a well-preserved ancient river delta on Mars
The Edinburgh team reviewed studies of fossils on Earth and assessed the results of lab experiments replicating Martian conditions to identify the most promising sites on the planet to explore for traces of ancient life.
They determined that sedimentary rocks made of compacted mud or clay are the most likely to contain fossils.
These rocks are rich in iron and a mineral called silica, which helps preserve fossils.
They formed during the Noachian and Hesperian Periods of Martian history between three and four billion years ago.
At that time, the planet’s surface was abundant in water, which could have supported microbial life.
The rocks are much better preserved than those of the same age on Earth, because Mars is not subject to plate tectonics – the movement of huge rocky slabs that form the crust of some planets – which over time can destroy rocks and fossils inside them.
The team say their findings could help inform NASA’s next rover mission to the Red Planet, which will focus on searching for evidence of past life.
WHAT IS NASA’S MARS 2020 MISSION?
The Mars 2020 mission is part of Nasa’s Mars Exploration Program, a long-term effort of robotic exploration of the red planet.
Nasa hopes the mission will help to answer key questions about the potential for life on Mars.
The mission also provides opportunities to gather knowledge and demonstrate technologies that address the challenges of future human expeditions to Mars, including producing oxygen from the Martian atmosphere, and identifying water.
The mission is timed for a launch in July/August 2020 when Earth and Mars are in good positions relative to each other for landing on Mars.
According to NASA, the new rover will have 23 cameras (artist’s impression pictured)
“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,’ Dr Sean McMahon, a Marie Sklodowska-Curie fellow in the University of Edinburgh’s School of Physics and Astronomy, said.
The US space agency’s Mars 2020 rover will collect rock samples to be returned to Earth for analysis by a future mission.
A similar mission led by the European Space Agency is also planned in coming years.
The study, published in Journal of Geophysical Research, also involved researchers at NASA’s Jet Propulsion Laboratory, Brown University, California Institute of Technology, Massachusetts Institute of Technology and Yale University in the US.