On the afternoon of February 18 (Earth time right here in Ohio), NASA’s most bold and complex rover will hopefully land on Mars to start out years of exploration round Jezero Crater. Much like NASA’s different rover missions — Spirit, Opportunity and Curiosity — the major objective of the Perseverence mission is to grasp the Martian geologic previous and probably discover proof of previous life on our subsequent neighbor out in the photo voltaic system.
So, why Jezero Crater (under)? Well, the geology of the 28-mile-wide crater performs the most essential function in why all of us hope that Perseverance will land efficiently in a few days.
The potential river delta deposits on the western facet of Jezero Crater on Mars, taken from MRO. Credit: NASA.
Jezero Crater is positioned alongside the margins of one of the bigger basins in the northern hemisphere of Mars. The crater is on the west facet of the Isidis Planatia, a giant impression basin stuffed by later sediment. Just to the south of the crater is a giant protect volcano referred to as Syrtis Major and off to the west are valleys referred to as the Nili Fossae.
Most strikingly, the space round Jezero Crater seems to be carved by rivers. A river valley referred to as the Neretva Vallis meanders in from the west after which exits on the east facet of the crater into the Isidis Planatia. This has lead geologists to assume that Jezero Crater was as soon as crammed with a lake fed by the river.
Mapping of the area by the Mars Reconnaissance Orbiter (MRO) not solely confirmed the exceptional topography together with the river channels, but in addition gave us a clue about the composition of the rocks in and round Jezero. A latest US Geological Survey map of Jezero Crater (sure, the USGS makes maps of different planets!) means that there are some fascinating and completely different rocks that could be associated to its watery previous.
The space of Jezero Crater on Mars the place Perseverance is hoping to land on February 18, 2021. Image: USGS.
Geology of Mars’ Wet Past
If you’ve got by no means regarded at a geologic map, they’re full of data. The space round the Perseverence touchdown ellipse (above) is color-coded for the completely different geologic items that may be outlined based mostly on the knowledge collected by MRO. The pinkish and salmon layers in the east (proper) are principally volcanic deposits that have been probably blown into the crater. It is a flat area, so a really perfect place to land the rover.
Off to the west (left) facet of the ellipse are the remnants of the potential Neretva river delta — deposits left as the river entered the proposed lake (all in blue on this map). Now, it has probably been over 3 billion years since the river flowed, so the river deposits at the moment are inverted topography. This signifies that what was once valleys at the moment are ridges, principally as a result of the river channel and delta deposits are extra proof against weathering. After Perseverence lands, the plan is to go to those highlands to look at the rocks in these outdated river and delta deposits.
One of the most attention-grabbing points of Jezero Crater is the proof from MRO that there are carbonates, clays and different minerals that probably require liquid water to kind. These deposits could maintain the proof of any life that might have emerged in the historic liquid floor waters of Mars.
Smack dab in the center of the delta is a small crater referred to as Belva that needs to be youthful than the delta. Just to the west (left) of the delta is the darkish brown unit labeled (cr) that’s the crater rim of Jezero. It is sort of 2,300 toes up from the base of the delta deposits to the crest of the rim. Beyond that’s hilly terrane that’s principally volcanic materials that make up most of the floor of Mars.
If all goes effectively, Perseverance will spend at least 3 years exploring this area. It carried newer variations of many of the imaging and compositional devices which can be on Curiosity. However, it additionally carries a floor penetrating radar referred to as RIMFAX that may map the shallower underground beneath the rover. So, we’ll know extra about the subsurface in addition to the floor.
The rover is powered by 11 kilos of plutonium oxide, so it is not depending on solar energy to maintain working. It can even cache samples alongside the manner for a potential pattern return mission so Earth geologists can (lastly) study Martian rocks in particular person. Why is that essential? For one, we will lastly measure absolute ages for Martian rocks utilizing radioactive parts in the rocks. We can even do different compositional analyses on the rocks utilizing devices that simply cannot be carted to Mars on a rover.
Mars could also be a dried up husk now. However, many individuals eye it as a potential future house for people. The Perseverence rover could not reply the query of whether or not life was harbored on Mars in the previous, however will nonetheless assist unravel its previous geologic historical past and possibly assist pave some of the manner for people to set foot on the pink planet.