Melting water in meteorites formed in the earliest days of the solar system could, according to a new study, lend credence to the theory that meteorites brought water and other precursors to our planet since billions of years.
Carbonaceous chondrites are a special group of meteorites that trace their origin back to the formation of the solar system. When parts of them were found on Earth, they were found to contain interesting pieces of information, such as minerals that only appear in water and organic fertilizers such as amino acids – some of the building blocks in life.
As a result, carbonaceous chondrites have become a major candidate for the depletion of water on Earth. A good way to know for sure would be if chondrite – which, although rare among the fallen meteoritic companions, still touches the Earth with consistency – comes to earth with water on it, and we were lucky enough to see the rock and get past it.
That is a high order. The asteroid Ryugu was recently it was found to be dry with water for a long time, long before Japan arrived there with her spaceship Hayabusa2. So far, scientists have noticed that fluid flow on carbonaceous chondrites occurred at some point, but they do not know how recently that flow may have occurred. Previous date methods showed that water was present on these rocks early – about 4.5 billion years ago, shortly after the Earth was formed.
“All of this leads to the idea that any change, and the presence of any water, was very ancient. So our test was to say, had there been a young change? ” Simon Turner, an isotope geoscientist at Macquarie University in Sydney, Australia, said in a video call. “Yes, there is still ice on these dragonflies.” Turner is the lead author of a new paper describing liquid flow in carbonaceous chondrites, published this week in the journal Scientific Reports.
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A team of researchers from Macquarie University, Florida State University, and the Paris Museum of Natural History have discovered that these carbonaceous chondrites contained a small amount of water in the last few hundred thousand years – most recently, as long as geological expanses and timescales will.
All meteorites fall, but only those that are seen falling are called “falls” after that. Turner’s team only used carbonaceous chondrite falls in their research, as these new rocks have a clear timeline of where they arrived and a context for what they communicated with on Earth (i.e. the objects which may be contaminated). The meteorites included in the study came from all over: One was from Sutter’s Mill, where the California Gold Rush began, and another came from a frozen lake in Russia, among many other sites around the world. -world.
The research team took samples from these space rocks and dated their water flow with uranium-thorium outflow, in which isotopes of both elements can be measured to identify age. In this case, the question was not the age of these dragons themselves, but the age at which liquid moved within the rock. Uranium is highly mobile in water, although thorium is not, so seeing as the uranium moved inside the meteorite relative to the thorium, the team could go down when the the water swims around.
“If there was ice on the bodies, and if there was a reason for ice to melt and move, and it happened within the last million years, you should expect a different behavior. uranium and thorium, ”said Turner.
In other words, when liquid flows, whether on a space rock or beside a river bed, it moves isotopes around, leaving a short-term record of the flow. That signature will disappear if too much time passes. If the isotopes were to move within a million years, in particular, the team would detect that disturbance.
How fresh the liquid is a movement found in some of the team’s samples is encouraging – it means that carbonaceous chondrites could have ice, if they had flowed liquid so a few hundred thousand years ago.
Edward Young, a recent geologist at UCLA not affiliated with the paper, said in an email that the new research was “very interesting” and “elegant. He noticed that other man scientists have just learned about the vast expanse of water on the asteroid Bennu, thanks to NASA follow up OSIRIS-REx Mission.
The next step is to test space rocks that did not fall like a fireball through the Earth’s atmosphere, a brutal process that empties just as ice melted on these asteroids (samples taken by a ship would -useful space). Meanwhile, researchers revolve around the collapsed space rocks, monitoring the skies for new evidence that may come down.