Scientists may be able to determine whether there has ever been life on Mars because to rocks found in the Australian Outback that date back 3.5 billion years.
Only ancient bacteria, according to scientists researching the Australian rocks, could have moulded them into what they are now.
They advise NASA’s Perseverance rover to search for similarities when studying rocks on Mars that are comparable in age.
The wheeled robot is looking for proof that early in the Red Planet’s history, biological established itself.
Researchers from the Natural History Museum in London and NASA have identified a variety of details in a group of domes in western Australia that are undeniably the work of ancient bacteria.
A big crater named Jezero is being explored by Perseverance, and it is anticipated that spots will be found there next year that may exhibit characteristics tantalisingly similar to those seen in the rocks of Earth.
These stromatolites are instances of preserved stromatolites.
They are produced when silt and microorganisms in layers as thin as a millimetre accumulate over time to take on bigger, dome-like structures. Today, these structures can be found near placid, nutrient-rich lagoons. However, the Australian Outback has retained instances from billions of years ago.
In fact, several of the Australian specimens discovered by geologists rank among the planet’s earliest signs of life.
Dr. Keyron Hickman-Lewis and colleagues from the Natural History Museum (NHM) in London carefully examined a particular collection of stromatolites. They belong to the Dresser Formation in the Pilbara region of the Australian Outback and are the oldest fossils ever found. They date back 3.48 billion years.
They don’t even have any organic (carbon-rich) chemicals that could represent signs of former life, let alone tiny fossils of bacteria. However, the NHM-led research believes it has identified signs that distinguish the rocks’ biological origin.
The scientists employed a variety of high-resolution analytical and imaging techniques to describe features that, in their opinion, can only really be described by the activity of life and not by something that might naturally occur in the environment.
The undulating top surface of the stromatolites, which develops when photosynthetic bacteria move toward the light, is one large-scale feature. Because biology does not expand in three dimensions at the same rate or in the same manner, undulations appear.
The connections between the many “mats” of microorganisms that form the stromatolites can be seen as small columns or pillars within the rock.
Dr. Hickman-Lewis stated, “These are strongly, strongly typical of a type of microbial development texture, which we call palisade structures.
Palisade structures are well known from habitats on the present Earth; examples that are comparable in size and organisation can be found. He told BBC News that these “occur very substantially in these domed growth stages.
The Jezero Crater appears from satellite imagery to have hosted a sizable lake in its deep past, which is relevant to Mars and the Perseverance rover. Additionally, there are carbonate rocks along the crater’s edge that might be deposits from the beach.
In Jezero’s quiet, nutrient-rich, shallow waters, might there have been bacteria building stromatolites?
It wouldn’t be too different from Earth’s timeframe; it would simply be a little early. The lake may have existed 3.7 billion years ago, according to scientists.
The crater edge will most likely be reached by perseverance by the end of the following year. When that happens, it will start using its equipment to look for rocks that resemble some of the Pilbara stromatolites.
Dr. Hickman-Lewis and Prof. Caroline Smith, who oversees the NHM’s Earth science collections, are also contributing to the rover project.
She stated that some of the rover’s inquiries would be guided by what they had learned from Australia in search of such recognisable organic traces.
“We could detect some of them using the rover’s imaging equipment, but that would rely on a number of factors, including whether stromatolites were present in the first place and how well preserved they may be.
Do they have a greater degree of macro or micro preservation? Are they widespread, or perhaps they will only be found in a specific region. Therefore, if we’re seeking in the incorrect spot, we might not find them, she advised.
It’s a really long shot to make a confident identification of ancient biology in Jezero Crater. Finding rock samples that are excellent candidates for future investigation back on Earth is more likely.
Drilling and storing samples that can be recovered by subsequent missions and transported back to Earth for examination is the main goal of Perseverance.
It will be challenging to demonstrate the existence of life, but Dr. Hickman-Lewis is confident that his team’s research has created a template for doing so: “If an archaeologist discovered the foundations of a ruined city, they would nonetheless know it was built by people because it would bear all the hallmarks of being built by people – doorways and roads and bricks. Similar to this, stromatolites have a variety of structural components that are essential to their formation and help us understand where they came from.
Geology has published an examination of the earliest stromatolites found on Earth.