It’s straightforward to take it with no consideration, however we’re driving round on freakin’ Mars proper now.
We’ve finished this a number of instances earlier than, certain, nevertheless it stays one among humankind’s most spectacular technological feats. The most recent rover to proceed our presence on the crimson planet is Perseverance, the star of the Mars 2020 mission that launched in July of that yr and landed in February of 2021.
It has now been busy roving for over two years. Information of what we’re discovering—past the stream of photographs—tends to return in discrete bits that may be laborious to attach into a much bigger image in the event you aren’t following intently. Take into account this your wide-angle recap.
Like different rovers, Perseverance is bristling with science devices. It has cameras of a number of varieties used each for basic imagery and spectral evaluation that may determine minerals. That latter perform is supplemented by an extra X-ray instrument. Perseverance additionally has a ground-penetrating radar instrument that may reveal layering hidden under the floor. Extra invasively, there’s a drill on the tip of the rover’s robotic arm. That is used to grind clear (what geologists name “recent”) spots for evaluation, however it will possibly additionally core out small cylindrical rock samples—hopefully to be retrieved and returned to Earth by a future mission.
It isn’t all concerning the rocks, although. Perseverance has a climate module monitoring atmospheric situations and airborne mud. And it has a good friend—the Ingenuity helicopter has wildly exceeded its pilot-testing purpose and remains to be flying briefly hops to maintain up with the rover.
This mission set down in Jezero Crater, which was chosen as a result of rocks resembling a river delta are draped over its rim—indicating that flowing water may need met a lake right here previously. It’s the right surroundings to check the historical past of water on Mars and the potential for life related to it. There’s solely a lot science you are able to do from orbit. To untangle the forensic clues that stay right here, you’ll want to get down on the bottom.
First cease: Crater
The primary years on Mars had been spent investigating the ground of Jezero Crater. The kind of rock that might be discovered right here was really considerably ambiguous from orbit. There was clearly some igneous rock, both from volcanic magma or a molten pool created by the meteorite influence that shaped the crater. However some additionally anticipated to see sedimentary rock representing the underside of a lake that known as the crater dwelling.
It turned out to simply be igneous basalt underneath the blanket of wind-blown mud, and any lake-bottom sediments that existed right here will need to have lengthy since eroded away. You would possibly suppose that’s disappointing—just like the pharaoh’s tomb was already cleaned out by grave robbers—however that is really one of many higher seems we’ve gotten at Mars’ igneous bedrock. Missions have typically focused pockets of notable sedimentary rock, with solely scattered bits of the rather more widespread igneous rock on show.
The Martian meteorites we’ve discovered on Earth—chipped off the crimson planet throughout massive influence occasions—have solely given us literal fragments of the large image. If we efficiently return the eight rock samples collected from the crater flooring, this chance to cruise round on intact igneous bedrock might reply quite a lot of questions raised by the meteorites.
On this case, the science group has divided the crater flooring rocks they noticed into two main layers. The higher one, known as the Máaz formation, seems to have shaped from lavas. Some parts exhibit a texture just like the wrinkled (or “rope-like”) lavas we see in Hawaii. In different areas, the rock occurs to stay up by means of the crimson mud as flat polygons resembling pavers in a backyard, or as taller, boulder-sized blocks.
The decrease Séítah formation is distinct in each texture and minerals. It stands out from its environment because of its skinny layering and visual, intently packed crystals. And whereas the Máaz rocks comprise a lot of the mineral feldspar, Séítah’s rocks are dominated by olivine, as an alternative.
This seems like what geologists name “cumulate”—the magmatic equal of the gritty dregs in your espresso cup. As a result of completely different minerals crystallize at completely different temperatures (sure, molten rock has a freezing level), minerals like olivine that crystallize early can settle to the underside of a magma physique and accumulate. On Earth, this sample could be seen in magma chambers that cooled underground or in some sufficiently thick lavas.
