Marsquakes reveals the ultra metallic nature of the Red Planet’s core
Scientific discoveries on Mars can be so shallow – hunting for water caches, terrestrial sampling, and other technical wonders tend to take place on the surface of the Red Planet (or a little above). But as NASA’s Perseverance rover roams the dust and gravel of Mars, there is also a lot deep down on the planet worth learning. Like the fact that the inner core of Mars is perhaps the most metallic place on the entire planet.
Discovery – Earlier this year, Three papers published in the review Science confirmed that the core of Mars is made of molten metal. The discovery is the result of recording earthquakes on Mars – the Martian equivalent of earthquakes here on Earth.
Mark the panoramic, the scientist for the JPL project for the NASA InSight lander, and his colleagues drew on data from the seismometer to find the thickness and potential structure of the planet’s crust, the temperature of the planet’s mantle, and make the first direct seismological confirmation of the planet’s core – hence the trio of papers.
REVERSE countdown the 20 scientific discoveries that made us say “WTF” in 2021. It’s # 7. See the full list here.
How they did it – Scientists know the Earth’s interior through seismology – essentially by studying earthquakes and other internal rumblings as a means of examining the processes that drive them – but this method hasn’t really been an option for researchers. who study other planets until very recently.
Then, in 2018, a seismometer landed on Mars as part of the NASA InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) mission – and it has been recording the tremors of Mars ever since.
The purpose of this mission is to discover the internal structure of Mars through seismological and thermal readings taken from a point on a plane along the Martian equator, called Elysium Planitia.
Dig into the details – In the study of the nucleus of Mars, InSight detected a type of seismic wave called an S wave, but these waves bounced off the core of the planet, making them ScS waves, to use scientific jargon. By tracking the waves and making other measurements, the researchers found that the core of Mars had a radius of about 1,800 kilometers and that it was liquid. Very similar to that of Earth, in fact.
“A strong nucleus wouldn’t have produced a strong enough reflection that we saw it,” Panning explained at the time.
“The fact that we recorded it confirmed that the core is liquid.”
In all of the studies, the researchers had to look for the signals they needed – it seems earthquakes on Mars aren’t as strong as earthquakes can be, at least according to this data.
“None of these events are big,” Panning says. “Perhaps the biggest event we’re looking at is a magnitude of 3.8,” he says. In California, where Panning is based, “there’s a very good chance you won’t even feel it, depending on how close you are. “
The extraordinary sensitivity of InSight’s seismometer can clock vibrations at the scale of a hydrogen atom, so its measurements are reliable. That Mars is dry and devoid of Earth’s noisy oceans also helps.
InSight also measured the two layers above the core: the mantle and the crust of Mars. Understanding the inner makeup of Mars is so important because it will help us understand how other rocky planets formed and evolved. The planet we live on is also a rocky planet.
InSight will continue its mission until 2022, digging deeper for answers and recording more earthquakes. And if we ever learn enough about Mars, the good news is that there are two other relatively nearby rocky planets that we need to investigate.
REVERSE countdown the 20 scientific discoveries that made us say “WTF” in 2021. It’s # 7. Read the original story here.