According to Stanford University Mars experts, NASA’s latest Martian rover will drive a wave of exciting discoveries when it lands on the Red Planet – and possibly alter scientists’ understanding of the blue one it launches from.

Despite a global pandemic and some technical delays, NASA’s 2020 Mars Rover – the aptly named Perseverance – is scheduled to launch this summer (currently slated for July 30) on a groundbreaking endeavor. Traveling from Earth to Mars is best done when the planets orbit nearest one another, providing only a narrow window of opportunity (rover pun intended) between mid-July and mid-August to start the journey. Its success will be the opening salvo in an ambitious series of missions designed to bring samples of Martian crust to Earth for the first time for study.

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“Rovers are the closest we can get to having a geologist on Mars at the moment, so any new rover data is really valuable,” said Mathieu Lapôtre, an assistant professor of geological science at Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth) who researches the geological processes that shape planetary surfaces. “Every time we have a rover like this, a wave of discoveries follows. It’s a very exciting time.”

Stanford scholars have a long history of contributing to NASA’s space missions – including the design of technologies sent into space, guidance and control of spacecraft. That tradition continues with this latest Mars mission. For example, Marco Pavone, a former research technologist at the NASA Jet Propulsion Laboratory (JPL), helped develop algorithms to optimize the selection of landing spots on Mars – in the case of Perseverance, an ancient meteorite impact site known as the Jezero Crater, or the Jezero Delta.

Even though NASA has an impressive track record of landing rovers on Mars, Pavone cautions against underestimating the adventure ahead. “Landing on Mars is a tremendous challenge,” said Pavone, an associate professor of aeronautics and astronautics and director of Stanford’s Autonomous Systems Laboratory. “Even if we did it successfully in the past, it is certainly not a done deal.”

Building upon a history of Mars missions

Perseverance is the fifth Mars rover from NASA, following Curiosity, Opportunity, Spirit, and the original Mars rover, Sojourner, named for civil rights activist Sojourner Truth. That first trailblazing rover arrived on Mars in 1997 equipped with few instruments and only able to venture roughly 40 feet from its lander, Pathfinder. “But the key requirement to demonstrate mobility on another planet was met,” said Scott Hubbard, an adjunct professor of aeronautics and astronautics at Stanford; Hubbard was the first Mars program director at NASA Headquarters, where he earned the nickname of “Mars Czar.”

Each rover since Sojourner has been sent to Mars with more sophisticated instruments, expanded capabilities and more ambitious goals. Curiosity directly preceded Perseverance and has the most in common with it, including size – which is roughly that of a small SUV. “To save money, the Perseverance rover was required to be a near duplicate of Curiosity wherever possible, even using leftover parts,” said Hubbard, who also authored Exploring Mars: Chronicles from a Decade of Discovery.

Perseverance will pick up where Curiosity left off. After landing in February 2021, the rover will roam the planet for at least one Mars year, which is roughly equal to two Earth years. Its tool suite includes a novel drilling and storage mechanism to extract and cache roughly 30 rock samples. This is the rover’s most critical function, according to Hubbard, because the plan is to retrieve those samples with a future “fetch rover,” shoot them into Martian orbit and eventually return them to Earth, where they will be analyzed for “fingerprints of life.” “Getting those samples back to Earth has been the ‘holy grail’ of Mars science for almost 50 years,” Hubbard said.

Once the Martian rocks are on Earth, they will be quarantined for safety, and then subjected to a battery of tests and measurements that cannot be performed on Mars itself. “With Curiosity, we are looking for habitable environments and organic molecules,” said Lapôtre. “But without bringing the samples back to Earth, it is really difficult to tell for sure if what we found was biogenic – formed by something that was alive – or abiogenic, meaning the organic molecules are not related in any way to life.”

It’s been a long road to reach this point. When the Mars Exploration Program was being revived by Hubbard’s team in the early 2000s after two mission failures, he believed the scientific, engineering and technology requirements of a sample return mission were too daunting to tackle. “Twenty years later, the suite of missions, orbiters and rovers that came out of our re-planning effort have yielded a wealth of knowledge about the Red Planet,” said Hubbard, “including the ability to now select the all-important site for a sample return.”

Location, location, location: Picking the right landing site

Real estate agents will tell you that the value of a property has more to do with location than anything else; a landing site is not much different. Pavone describes the process of selecting the site as finding the “sweet spot” on the planet’s surface that strikes a balance between scientific potential and risk to the rover.

“This specific landing site was chosen because of its promise in terms of astrobiological potential,” said Lapôtre. “In my opinion, it was very well chosen. Whether we find evidence for ancient life or not, I am convinced that we will learn a lot about the ancient environment on Mars.”

Jezero Crater was once a lake formed by an ancient river filling a meteor impact crater. “It makes for a great place to look for evidence of life,” said Lapôtre, “because, like the Nile or the Mississippi, this river likely picked up sediments and any forms of life that may have existed along its course and concentrated them in one place.”

The Jezero location is also older than previous rover landing sites – somewhere around 3.7 billion years, which is when scientists believe Mars may have been habitable. Any life on Mars at the time would consist of simple unicellular organisms like microbes. So scientists must look for biomarkers – pieces of organic molecules or chemical indicators – that these living things could have left behind in the rocky surface, rather than bones or fossils.

Another advantage of this site is that it could allow scientists to test the hypothesis that ancient organisms on Mars lived in the subsurface. “This crater punctured through the Martian surface to expose ancient rocks,” said Janice Bishop, a senior research scientist for the SETI Institute and a Stanford alumnus. Bishop utilizes remote sensing to study rocks on the surface of the Red Planet to gain insights about Mars’ watery past, so this mission is of particular interest as the selected landing site features an ancient river delta. “Perseverance is expected to reveal secrets about the early history of water on Mars,” Bishop added.

Like Mars, Earth was devoid of large organisms for most of its history, such that its geological processes were largely unaffected by macroscopic life. However, Earth’s surface is constantly recycled through the continual shifting of continent-sized plates; this process is known as plate tectonics and does not occur on Mars. “A lot of us are super excited about how this information could improve our understanding of Earth before there was life,” said Lapôtre. “I will definitely use the mission data in my research program, and have PhD students combine rover and orbiter data to answer questions about the geologic history of Mars.”

Information gleaned from the ancient river that once emptied into Jezero crater could change how scientists think about how rivers form, and tie into global carbon cycles and climate – not only on Mars but also Earth and other planets.

Testing new technologies on Mars

Perseverance will be breaking new technological ground as well on this mission. “Continuing in the tradition of using each Mars mission as a technology test-bed for new future capabilities, the rover will bring along a very small, four-pound helicopter,” said Hubbard. Dubbed Ingenuity, the copter will be the first flying vehicle on another planet and will have to navigate the frigid nights and dust-filled skies of Mars while operating in an atmosphere that is 100 times thinner than Earth’s.

“Sojourner was itself a technology demonstration to prove wheeled mobility on Mars,” said Pavone. “Who knows what we’ll be able to do another 20 years down the road once we prove we can fly helicopters on Mars?”

Nineteen high-resolution cameras on the 2020 rover should provide unprecedented images of the Martian surface, as well as the landing process. Perseverance is also equipped with an instrument called Moxie, which will test the potential of converting Mars’ thin atmosphere into oxygen for future human explorers.

“If this were a perfect world, humans will be arriving on Mars in 2033,” said Hubbard. “This seems to be far in the future, but it is literally around the corner in space mission terms.”

Quelle: Stanford University

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Nasa Mars rover: Meteorite to head home to Red Planet

A small chunk of Mars will be heading home when the US space agency launches its latest rover mission on Thursday.

Nasa's Perseverance robot will carry with it a meteorite that originated on the Red Planet and which, until now, has been lodged in the collection of London's Natural History Museum (NHM).

The rock's known properties will act as a calibration target to benchmark the workings of a rover instrument.

It will give added confidence to any discoveries the robot might make.

This will be particularly important if Perseverance stumbles across something that hints at the presence of past life on the planet - one of the mission's great quests.

"This little rock's got quite a life story," explained Prof Caroline Smith, head of Earth sciences collections at the NHM and a member of the Perseverance science team.

"It formed about 450 million years ago, got blasted off Mars by an asteroid or comet roughly 600,000-700,000 years ago, and then landed on Earth; we don't know precisely when but perhaps 1,000 years ago. And now it's going back to Mars," she told BBC News.

 

Discovered in the deserts of Oman in 1999, the meteorite, known as Sayh al Uhaymir 008, or SaU 008, is a classic piece of basalt - very similar to the type of igneous rock you will find, for example, at Giant's Causeway in Northern Ireland.

It contains lots of pyroxene, olivine and feldspar minerals. And it's this well-studied chemistry, together with the meteorite's textures, that make it so useful for Perseverance.

The rock has been put in a housing, along with nine other types of material, on the front of the rover where it will be scanned from time to time by the Sherloc instrument.

This is a tool that contains two imagers and two laser spectroscopes, which together will investigate the geology of the rover's landing site - a 40km-wide crater called Jezero.

Satellite images suggest the bowl once held a lake, and scientists consider it to be one of the best places on Mars to try to find evidence of past microbial activity - if ever that took place.

Image copyrightPA MEDIA

Sherloc will study the local rocks and soil, looking for signatures of ancient biology.

What scientists don't want, however, is to have what they think is a "eureka moment" only to then realise Sherloc had developed some systematic error in its observations.

"We'll look at the calibration target in the first 60-90 days and perhaps not again for six months because we think the instrument is really very stable," said Dr Luther Beegle, Sherloc's principal investigator from Nasa's Jet Propulsion Laboratory.

"But if we start seeing interesting things on the surface of Mars that we can't explain in the spectra, then we'll look back to the calibration target to make sure that the instrument's working correctly.

"I think the best we're going to be able to do from a scientific perspective is identify what we would call a 'potential bio-signature'.

"I don't think we'll ever be necessarily 100% sure because that's a hard measurement to make, which is why the sample-return aspect of Perseverance is so important."

Image copyrightNASA-JPL

The rover will package its most interesting rock samples into small tubes that will be left on the surface of Mars for retrieval and return to Earth by later missions.

Prof Smith is hopeful she'll get to work on this material, which could come back in the next 10-15 years.

The NHM expert is on an international panel that will determine how best to handle the extra-terrestrial rocks.

"I'm actually leading the curation focus group," she told BBC News. "By this time next year, we should have a really good plan for the sort of building we will need, the types of processes that will be happening in that building, and how we'll actually start curating the samples and making them available to scientists for study."

 

Researchers will have a much better chance of confirming life on Mars if they can assess the evidence using all the analytical tools available in Earth laboratories, as opposed to just the small suite of instruments carried by a robot rover.

Nasa's Perseverance rover is scheduled to lift off on a United Launch Alliance Atlas rocket from Cape Canaveral, Florida, during a two-hour window on Thursday that begins at 07:50 local time (11:50 GMT; 12:50 BST).

The slice of SaU 008 won't be the only Martian meteorite on board. The rover's SuperCam instrument will have its own piece of Mars rock, again to act as a calibration target.