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Planets: Mars

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March 21, 2019
7 Theories on the Origin of Life
March 21, 2019

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A Nasa robot being tested in the most Mars-like environment on Earth has found samples that could help humanity find alien life, scientists say. The rover pulled up soil samples from beneath the Earth that contained strange and highly specialised microbes that were spread out in patches. The unusual discoveries appear to have developed to deal with the very limited amounts of water and nutrients in the soil, as well as its chemistry. The discovery not only shows that the lander will successfully be able to search for any potential life on Mars or elsewhere, but also shows the first time these particular hardy microbes – which could be similar to any currently living on the red planet – have been discovered. The findings have been published in the journal Frontiers in Microbiology and scientists say they will help the search for signs of life when future missions head to Mars.



The very fact that subsurface soil of this kind could be found in the Atacama Desert in Chile is a breakthrough that will drive future discoveries, scientists said.

"We have shown that a robotic rover can recover subsurface soil in the most Mars-like desert on Earth," says Stephen Pointing, a Professor at Yale-NUS College, Singapore, who led the microbial research said in a statement. "This is important because most scientists agree that any life on Mars would have to occur below the surface to escape the harsh surface conditions where high radiation, low temperature and lack of water make life unlikely. "We found microbes adapted to high salt levels, similar to what may be expected in the Martian subsurface. These microbes are very different from those previously known to occur on the surface of deserts."

Both Nasa and the European Space Agency are preparing to send rovers to Mars in 2020. Those will roam over the surface and look for evidence of life, either in the past or the present, as well as drilling under the surface in an attempt to pull up any microbial life that might be hiding beneath there. Testing of this kind helps ensure that the missions succeed and shows that rovers should be able to deal with the harsh environment on Mars. "The core of the Atacama Desert in Chile is extremely dry, experiencing decades without rainfall. It has high surface UV radiation exposure and is comprised of very salty soil. It's the closest match we have on Earth to Mars, which makes it good for testing simulated missions to this planet," said Pointing in a statement. The rover was put into the Atacama Desert to see if it would be able to pull up sediment samples as deep as 80cm beneath the surface. The samples it did gather were then compared with those taken by hand – and researchers found they were similar, suggesting that the rover was a success.



The same test also found the microbes were living in patches across the surface, related to the difficult environment in which it was living.

"These results confirm a basic ecological rule that microbial life is patchy in Earth's most extreme habitats, which hints that past or present life on other planets may also exhibit patchiness," explain study co-authors Nathalie Cabrol and Kim Warren-Rhodes of The SETI Institute. "While this will make detection more challenging, our findings provide possible signposts to guide the exploration for life on Mars, demonstrating that it is possible to detect life with smart robotic search and sampling strategies." Scientists now hope they can drill even further into the surface and see how deep microbial life might be able to thrive. "Mars missions hope to drill to approximately 2m and so having an Earth-based comparison will help identify potential problems and the interpretation of results once rovers are deployed there," said Pointing. "Ecological studies that help us predict the habitable areas for microbial communities in Earth's most extreme environments will also be critical to finding life on other planets."



Signs of ancient rivers on Mars revealed in new images

Images taken by the European Space Agency’s Mars Express satellite show the marks that an ancient network of rivers have left on the planet’s surface. The valleys formed as they would on earth, with a strong flow of water carving its way through the landscape. What is less clear is where the water came from. Due to a lack of knowledge about the past climate of Mars, scientists can not tell whether it came from groundwater, precipitation, melting glaciers or something unheard of. There is no liquid water on the surface of mars today, though plenty of similar ex-water features have been discovered in recent years, suggesting Mars once had a far wetter and warmer climate.

Each discovery raises further questions about the planet's past atmosphere and scientists ultimately want to know whether or not it would have been suitable for life. Next year the ESA in collaboration with Russia’s space program Roscomos will launch the ExoMars mission with the primary goal to “address the question of whether life has ever existed on Mars".

Nasa 'well on its way' to finding alien life with Mars project, says boss

Nasa is “well on its way” to finding alien life, its boss has said. The space agency is involved in a whole host of projects looking for traces of life elsewhere in the solar system, and has regularly speculated on how far away it might be discovering it.



On various planets and places throughout the universe, it has said there might be the possibility that life could flourish. But now it says that it is getting close to actually detecting traces of life. As the space agency said goodbye to the Opportunity rover – which helped show that Mars is more active and interesting than we might have suspected – administrator Jim Bridenstine said that Nasa would continue to search for such life. And, he said, it wasn’t that long away from discovering it. Future missions should allow scientists to collect samples from the Martian surface and hopefully bring them back to Earth, allowing them to look through in the hope of finding “biosignatures” left behind by living things.

“We’re going to be able to look at samples and determine if there’s a biosignature in there,” Bridenstine said in comments first reported by Space.com. “The goal is to discover life on another world; that’s what we’re trying to achieve. And because of so many great people in this room, friends, we are well on our way to doing that.”

He noted that a whole host of observations from Mars showed that it could be a promising place for life to have once lived – or still be. It has been found to have the building blocks of life in complex organic molecules, as well as water floating beneath its surface.



Nasa hasn’t ever found evidence that life exists or even could exist on Mars or anywhere else in the universe. But they do suggest that it could be a better than expected place for it to be, and makes the discovery more likely.

“All of these things collude to say there is a lot we need to learn, and friends, we’re going to do it quickly,” Bridenstine said.

Nasa's Mars rover is officially dead, space agency says

Nasa's Opportunity rover is officially dead, the space agency has said, after it disappeared in a dust storm on Mars. Clearly emotional Nasa staff, standing in front of a life-sized replica of the rover, said they had not heard back from the rover and that the mission would come to an end. Scientists described the difficult process of saying goodbye to the rover, which they had nicknamed Oppy and described as being like a beloved member of the family. "I am standing here with a sense of deep appreciation and gratitude," said Nasa associate administrator Thomas Zurbuchen, before he announced that the Opportunity mission is now considered complete. The robot set a huge number of records as it travelled across the Martian surface, eventually travelling some 28 miles and lasting far longer than any other Mars lander. It discovered that water once flowed on the planet and lit up the world with the possibility that it might once have been able to support life.



But in June – after sending messages back to Nasa that indicated it was getting dark and its batteries were running low – the rover went silent. A vast dust storm had covered the entire planet and is thought to have covered up the solar panels that provided Opportunity with its power, leading it to shut down.

Nasa sent more than 1,000 messages to try and wake up the rover and get it working once again. But its last try was sent on Tuesday evening and went unanswered, leading the space agency to declare the rover dead. It brought an end to 15 years of exploration over the red planet. Opportunity arrived at the beginning of 2004 alongside an identical twin known as Spirit for a mission that was only intended to last just three months and travel only 1,000 meters.

Nasa last heard from Opportunity on 10 June. Flight controllers kept trying to re-send messages to try and wake the rover back up – but even when the dust storm cleared and sunlight should have been getting through, no response was received. The historic last message was sent from the 70-meter Mars Station antenna at at NASA's Goldstone Deep Space Complex in California. It brought an end to an eight-month effort during which engineers said they tried everything they could to get the rover to wake back up.



“We have made every reasonable engineering effort to try to recover Opportunity and have determined that the likelihood of receiving a signal is far too low to continue recovery efforts," said John Callas, manager of the Mars Exploration Rover project at Nasa's Jet Propulsion Laboratory. Scientists had always expected that the rovers would be killed off by the dust on Mars – but thought that it would happen in just a few months. Instead, they found that the winds on the planet blew that dust off when it accumulated, helping to clear the rover and allowing it to last for much longer than expected. Engineers think the internal clock might have become scrambeld by the long outage, meaning that the rover woke up at the wrong time and drained its batteries. Opportunity had to go into deep sleep every night to ensure that its batteries kept enough power – but the disruption probably meant that it lost its sense of time, and so forgot when it needed to go to sleep.

Mars is now heading for an extended cold spell that will probably destroy the components powering Opportunity forever. Scientists are unlikely to ever know why both Opportunity and Spirit died.



Opportunity's death means that Curiosity is the only functioning rover on the planet's surface. Many more are expected to join it – the ExoMars rover, for instance, an international project that hopes to look for signs of life – with two new robots expected to arrive next year. Engineers and scientists said Spirit and Opportunity would live in on in the legacy they leave behind for the rovers and orbiters that will go on to further explore the mysterious ground of the planet that Opportunity spent so long scouting around.

"For more than a decade, Opportunity has been an icon in the field of planetary exploration, teaching us about Mars' ancient past as a wet, potentially habitable planet, and revealing uncharted Martian landscapes," said Zurbuchen in a statement. "Whatever loss we feel now must be tempered with the knowledge that the legacy of Opportunity continues – both on the surface of Mars with the Curiosity rover and InSight lander – and in the clean rooms of JPL, where the upcoming Mars 2020 rover is taking shape." Opportunity will now rest at the edge of Perserverance Valley, just one of the wide variety of craters, hills and other geological features that the rover explored as it made its record-breaking journey across the surface. "I cannot think of a more appropriate place for Opportunity to endure on the surface of Mars than one called Perseverance Valley," said Michael Watkins, director of JPL. "The records, discoveries and sheer tenacity of this intrepid little rover is testament to the ingenuity, dedication, and perseverance of the people who built and guided her."