NASA pins down where Mars 2020 rover will search for life
Meteorologist/Science Writer
Monday, November 19, 2018, 5:43 PM - A crater named Jezero will become the focal point of NASA's search for life on Mars. Here's why the agency decided on this location to send their next rover mission.
After an exhaustive search and decision-making process, NASA has finally pinned down where they are sending their next Mars rover.
Jezero, a 45-km-wide impact crater in Mars' northern hemisphere, is named after a town in Bosnia-Herzegovina, where the name literally translates to 'lake'.
Overlaid on this false-colour Mars topography map (from the Mars Orbiter Laser Altimeter, on the Mars Global Surveyor spacecraft) are the locations of the various NASA Mars missions, including the latest InSight, and the newly chosen landing zone for Mars 2020. Credit: NASA/JPL-Caltech/Scott Sutherland
This name is very appropriate, because according to NASA, the crater was once home to a lake, fed by a wide river delta along its western rim, which "could have collected and preserved ancient organic molecules and other potential signs of microbial life from the water and sediments that flowed into the crater billions of years ago."
"The landing site in Jezero Crater offers geologically rich terrain, with landforms reaching as far back as 3.6 billion years old, that could potentially answer important questions in planetary evolution and astrobiology," Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate, said in a NASA press release. "Getting samples from this unique area will revolutionize how we think about Mars and its ability to harbor life."
The location of Jezero Crater, along the western edge of impact basin Isidis Planitia, on Mars. Credit: NASA/USGS/ESA/DLR/FU Berlin (G. Nuekum)/Google Earth/Scott Sutherland
From NASA's November 19 press release:
Jezero Crater’s ancient lake-delta system offers many promising sampling targets of at least five different kinds of rock, including clays and carbonates that have high potential to preserve signatures of past life. In addition, the material carried into the delta from a large watershed may contain a wide variety of minerals from inside and outside the crater.
The geologic diversity that makes Jezero so appealing to Mars 2020 scientists also makes it a challenge for the team’s entry, descent and landing (EDL) engineers. Along with the massive nearby river delta and small crater impacts, the site contains numerous boulders and rocks to the east, cliffs to the west, and depressions filled with aeolian bedforms (wind-derived ripples in sand that could trap a rover) in several locations.
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This image shows a false-colour view of the river delta along the western rim of Jezero Crater. The colourful formations on the right side of the image are from a spectral analysis from orbit, revealing the presence of sediments that have been chemically altered by water, such as clays and carbonates. Credit: NASA/JPL/JHUAPL/MSSS/Brown University
WHY SPECIFICALLY THIS SITE?
Jezero crater was one of over 60 sites being considered by the Mars 2020 team. So, what set it apart from the others, and carried it through to the finale?
NASA went through a few different rounds of deliberations, as it tried to decide where to send this new mission. Even as of February 2017, they still had eight candidates, and through one penultimate round of discussions, managed to narrow it down to just three.
Jezero was one. A nearby region of volcanic, layered features, known as Northeast Syrtis was another. Columbia Hills, in Gusev Crater (the permanent home of the Mars Spirit rover), on the other side of the planet, was the third.
Columbia Hills was attractive, since the Spirit rover had already revealed warm, wet conditions there in the past, where mineral springs flowed up to the surface at one point. Northeast Syrtis' volcanic activity meant that it was once warm and wet. Jezero was known, from the types of formations and sediments detected from orbit, to have been filled with lake water on two different occasions, with a dry period in between.
Both Northeast Syrtis and Jezero had an advantage, though. They were just 50 kilometres apart - relatively close to one another, even with the rover's slow top speed. The team even tried for a compromise, picking a spot midway between the two (which they appropriately named 'Midway').
The location of the final three landing locations under consideration for Mars 2020, along with the projected landing ellipses. Credit: ESA / DLR / FU Berlin / Emily Lakdawalla
Jezero, however, not only has an abundance of clays and water-affected minerals in its river delta, but there are also signs of impact craters in the delta as well. It's unknown when those impacts occurred, however since meteorites are potential sources of organic molecules, and recent findings indicate that wet-dry cycles could play a part in the development of life, this is a very attractive location, indeed.
Plus, with Midway and Northeast Syrtis close enough by, extended missions for Mars 2020 could have the rover driving up the river that once fed Jezero's lakes (on the left, in the image above), to eventually visit the other two sites, as well.
Watch below as this animation, from Robin L. Fergason, Andy Britton and Seán Doran, takes us on a simulated pass over Jezero crater, using real data from the Mars Reconnaissance Orbiter's Context Camera and MARCI camera.
(READ MORE: Catch up on the latest news about weather, climate and space from science writer Scott Sutherland, on The Weather Network's Out Of This World blog)
WHAT IS MARS 2020?
In NASA's continued exploration of the planet Mars, they are now building upon the work of previous missions, especially the Curiosity rover, to take things to the next level.
Mars 2020, which will likely have a name chosen for it prior to launch (in the same vein as Opportunity, Spirit and Curiosity), is NASA's next nuclear powered Mars rover.
This artist's concept drawing of Mars 2020 depicts the rover investigating the cracked bed of an ancient river delta. Credit: NASA/JPL-Caltech
Based on the same design as Curiosity, this new robot will include a different suite of instruments. Whereas Curiosity's mission was to search Gale Crater for "environments that were habitable to life as we know it", Mars 2020 will have the tools needed to go beyond that, to actually look for signs that living organisms did, indeed, inhabit those environments, long ago.
There's an added bonus for this mission, something which has never been done before. NASA is planning to send a helicopter along with Mars 2020, to help with its exploration of Jezero crater!
Watch below to see how a flying NASA drone will assist Mars 2020 in its mission.
The innovations with this mission don't stop there.
Not only will Mars 2020 include a new science suite, and this remote drone assistant, but the engineering team is upgrading the rover's landing system - the 'sky crane' descent stage. For Mars Curiosity, the sky crane simply flew down close to the surface, hovered in place using jets, lowered the rover to the surface on a long tether, then disconnected and flew away to crash.
With more potential hazards to deal with on the surface during Mars 2020's landing, this rover's descent stage will have a new capability, known as Terrain Relative Navigation (TRN). In addition to what Curiosity's sky crane could do, Mars 2020's will also be able to steer as it descends, to avoid anything that would damage the rover upon touchdown.
Mars 2020's new method of landing, including the Terrain Relative Navigation system. Credit: NASA/JPL-Caltech/Scott Sutherland
Additionally, the Mars 2020 rover will be the very first to gather materials for future 'sample return' missions. Basically, the rover will scoop up samples, lock them away in canisters, which will be left on the surface to be retrieved by a future mission, for return to Earth. Here, scientists can subject those samples to a range of tests - far more than could be done by any robotic mission we send, and far faster, as well.
Mars 2020 is currently scheduled to launch towards the Red Planet in July of 2020, and is expected to land in Jezero Crater in February 2021. With its landing zone now selected, the engineering team can focus its plans specifically on what they expect to find there, and the science team can set down plans for where the rover will visit, once it is on Mars.
Sources: NASA | NASA | The Planetary Society
