A meteorite that struck Earth more than 200 years ago could fundamentally change our understanding of how Mars formed.
Most of what we know about the interior of the Red Planet comes from three space rocks that landed on our planet after being ejected from Mars by impacts.
They include the Chassingy meteorite, which fell in northeastern France in 1815, and two others known as Shergotty and Nakhla.
A new analysis by Chassingy suggests that the inner chemical composition of Mars comes largely from meteorite collisions, rather than a giant cloud of gas called the solar nebula as previously thought.
It contradicts current thinking about how rocky planets like Earth and Mars acquire volatile elements such as hydrogen, carbon, oxygen, nitrogen, and noble gases as they form.
Mars has a special interest because it formed relatively quickly, solidifying in about 4 million years after the birth of the Solar System, while the Earth took between 50 and 100 million years to form.
Discovery: A new analysis of the Chassingy meteorite (pictured) suggests that the inner chemical composition of Mars comes largely from meteorite collisions, rather than a giant cloud of gas called the solar nebula as previously thought.
MARCH: THE BASICS
Mars is the fourth planet from the sun, with a dusty, cold, deserted ‘almost dead’ world with a very fine atmosphere.
Mars is also a dynamic planet with stations, polar caps, canyons, extinct volcanoes and evidence that it was even more active in the past.
It is one of the most explored planets in the solar system and the only planet humans have sent rovers to explore.
A day on Mars takes a little over 24 hours and a year has 687 Earth days.
Facts and figures
Orbital period: 687 days
Area: 144.8 million km²
Distance from the Sun: 227.9 million km
Gravity: 3,721 m / s²
Radius: 3,389.5 km
Monday: Phobos, Deimos
Scientists had thought that the newly formed worlds first collected these volatiles from the nebula around a young star, before the elements initially dissolved in an ocean of magma and then were released back into the atmosphere. while the planet is still a ball of molten rock.
The theory is that later chondritic meteorites that will crash into the young planet provide more volatile materials.
It was believed that the volatile elements inside the planet should reflect the composition of the solar nebula, or a mixture of solar and meteoritic volatiles, while the volatiles in the atmosphere would come mostly from meteorites.
This was supported by previous research on Chassingy that analyzed the isotopes of xenon, a chemically inert gas that can survive unchanged for millions of years.
The isotope ratios of the meteorite appeared to match those of Mars’ atmosphere and solar nebula, suggesting that its volatile elements, such as hydrogen, carbon, and oxygen, came from the Earth. solar nebula and that the additional elements came from later meteorites. .
However, the new study by researchers at the University of California, Davis discusses this.
They analyzed a sample of Chassigny, but this time they analyzed the isotopes of krypton, a different inert gas that allows more accurate measurements.
“With xenon isotopes, it is difficult to distinguish the precise source of volatiles, but this is not the case with krypton,” Sandrine Péron, one of the study’s authors, told New Scientist.
“With krypton, you can better see the difference between potential sources like solar or meteorites … but krypton isotopes are harder to measure than xenon isotopes, so it hasn’t been done before.”
The researchers found that the isotopes came from meteorites rather than the solar nebula.
This means that meteorites were delivering volatile elements to the planet in formation much earlier than previously thought, and in the presence of the nebula, reversing conventional thinking.
Mars has a special interest because it formed relatively quickly, solidifying in about 4 million years after the birth of the Solar System, while the Earth took between 50 and 100 million years to form.
“The Martian interior composition for krypton is almost purely chondritic, but the atmosphere is solar,” Peron said. “It’s very different.”
The results show that the atmosphere of Mars would not have formed only by degassing the mantle, as this would have given it a chondritic composition.
The planet must have acquired the atmosphere of the solar nebula, after the ocean of magma cooled, to avoid a substantial mixture between the inner chondritic gases and the atmospheric solar gases.
The new results suggest that Mars’ growth was completed before the solar nebula was dissipated by the sun’s radiation.
But the irradiation should also have expelled the nebular atmosphere from Mars, suggesting that the atmospheric krypton must have been preserved in some way, possibly trapped underground or in polar caps.
“However, this would require Mars to be cold immediately after its accretion,” Mukhopadhyay said.
“While our study clearly points to chondritic gases inside Mars, it also raises some interesting questions about the origin and composition of Mars’ early atmosphere.”
The study was published in the journal Science.
Explanation: The difference between an asteroid, a meteorite, and other space rocks
An asteroid is a large piece of rock left over from collisions or the first solar system. Most lie between Mars and Jupiter in the main belt.
A comet is a rock covered with ice, methane, and other compounds. Their orbits take them much further away from the solar system.
A meteor is what astronomers call a flash of light in the atmosphere when waste is burned.
This waste is known as a meteoroid. Most are so small that they vaporize into the atmosphere.
If any of these meteorites reach Earth, it is called a meteorite.
Meteorites, meteorites and meteorites usually originate from asteroids and comets.
For example, if the Earth passes through the tail of a comet, much of the debris burns into the atmosphere, forming a meteor shower.