The most surprising discovery in the recent exploration of the Solar System is the presence of water and ice on so many planets and satellites. We knew there was much water on Mars.. at least, at the poles. Latest surprise: how much ice seems to be present at the equator of Mars. Now Mars’ equator has nearly temperate temperatures, and much more exploitable solar power (as long as there is machinery to clean the panels!)
NASA’s InSight lander French made and operated seismometer recorded a magnitude 4 marsquake Dec. 24, 2021. That seismometer is the main feature of Insight. France’s Centre National d’Études Spatiales (CNES) provided the Seismic Experiment for Interior Structure (SEIS) instrument to NASA, with the principal investigator at IPGP (Institut de Physique du Globe de Paris)
The cause of that quake? A meteoroid strike, perhaps the biggest seen on Mars since NASA began exploring.
Completely unexpected and amazing, the meteoroid excavated boulder-size chunks of ice. Now this all happened close to the Martian equator — a discovery with joyous implications for future colonization plans.
Preceding impact craters on Mars had shown blue material in it, presumed to be water ice. But it’s not sure. The latest impact clearly shows what seems to be blocks of exploded ice laying on the surface. The crater is 150 meters across:
NASA’s Mars Reconnaissance Orbiter (MRO) spotted a new, yawning crater. The impact, in a region called Amazonis Planitia, blasted a crater roughly 492 feet (150 meters) across and 70 feet (21 meters) deep. Some of the ejecta thrown by the impact flew as far as 23 miles (37 kilometers) away.
The meteoroid is estimated to have spanned 16 to 39 feet (5 to 12 meters) — small enough that it would have burned up and exploded in Earth’s atmosphere…. but not in Mars’ thin atmosphere, which is just 1% as dense as our planet’s. Mars corresponds to altitude 21 kilometers on Earth
InSight has seen its power drastically decline in recent months due to dust settling on its solar panels. This crucial French seismoter will be left to freeze, an icy reminder that solar power goes only that far. NASA has finally understood that it has to go back to nuclear power: the latest robot there is nuclear power, and the fabrication of nuclear power sources has been relaunched… After decades of nuclear abandonement….
Some pseudo-ecologists will scoff, reading that having no nuclear power killed InSight. However, given enough time, the French seismograph could have elucidated this. For example the impact above is the first time surface marsquake waves were detected. Surface waves provide with a wealth of information, because they are material and frequency dependent… As I am writing these lines InSight is dying. RIP.
The solar system would be quickly conquered if we had a compact energy source, such as portable thermonuclear fire. It would enable fast travel and great habitability works
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InSight studies the planet’s crust, mantle, and core, thanks to seismic waves. It has revealed the size, depth, and composition of Mars’ inner layers. Since landing in November 2018, InSight has detected 1,318 marsquakes, including several caused by smaller meteoroid impacts.
December 2021’s impact was the first observed to have surface waves — the kind of seismic wave that ripples along the top of a planet’s crust.
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Mars crust is thinner than expected and may have up to three sub-layers. The crust goes as deep as 23 miles (37 kilometers) if there are three sub-layers.
Beneath that is the mantle, which extends 969 miles (1,560 kilometers) below the surface —twice as deep as on Earth. This could be because there is now only one continental plate on Mars, in contrast to Earth with its seven large mobile plates, within which water plays a key lubrificating role. At 650 kilometers deep on Earth, water disappears and the rock changes…. The thick lithosphere fits with the model of Mars as a ‘one-plate planet.
At the heart of Mars is the presumably molten core, which has a radius of 1,137 miles (1,830 kilometers). This is huge and surprising. It took hundreds of years to measure Earth’s core; after the Apollo missions, it took them 40 years to measure the Moon’s core. InSight took just two years to measure Mars’ core.
Because the core radius is large, the density of the core must be relatively low. Thus the core must contain a large proportion of lighter elements in addition to iron and nickel. These include sulphur, oxygen, carbon, and hydrogen, in unexpectedly large proportion. So the composition of the entire planet is not yet fully understood. Nonetheless, so far, investigations confirm that the core is liquid… even if Mars no longer has a magnetic field (perhaps because the core didn’t have enough iron).
Why such a big molten core? According to yours truly, nuclear reactions contribute to core formation. As Mars is much smaller than Earth, if such was not the case, Mar’s core would have long solidified. So the InSight’e result demonstrates my theory.
Planetary cores are crucial to questions of habitability of planets. Large Igneous Provinces (LIPs) caused several mass extinctions on Earth. They happen on the average every 15 million years, but vary in intensity. Two very large LIPs occurring together would probably destroy life on Earth, and Venus’ life and habitability may have succumbed to a LIP, 700 million years ago.
The disappearance of dinosaurs seems to have been caused by the Deccan/Reunion plume LIP, with maybe the added contribution of the Yucatan bolide as the last straw.
Studying the Solar System turns out to be surprisingly rich. William Shatner, who played commander of the Enterprise in the famous series Star Trek, ascended a bit into space recently. Shatner got shattered… By what he saw, namely, nothing.
Shatner: …”things that took five billion years to evolve, and suddenly we will never see them again because of the interference of mankind. It filled me with dread. My trip to space was supposed to be a celebration; instead, it felt like a funeral.”
Well Shatner didn’t look at what is right: water everywhere… Once we have colossal compact energy, that is, controlled thermonuclear fusion, we will be able to zoom fast between worlds we will create, we humanity, full of life, some by digging inside, others, why not, by living on the surface in reconstituted atmospheres…
LIPs on Venus and related implications for life in the galaxy, and Earth, will be for another essay…
Patrice Ayme
P/S: LIPs = Large Igneous Provinces, or how life could (have) become extinct on Earth, and how Venus, from balmy Eden, became a runaway greenhouse…
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