Melted meteorites are not the source of much of Earth’s water, researchers have found.
Previous research has shown that once-liquid space rocks are the source of H2O on Earth.
But the new findings show that their water content is actually extremely low; in fact, they are among the driest extraterrestrial objects ever measured.
Molten meteorites are so called because they consist of a type of rock called an achondrite, which formed after objects collided to form the early protoplanets of the solar system, many of which had crusts and molten cores, but later Crack, or have debris cut them off, releasing new objects that start traveling through space.
Professor Megan Newcombe of the University of Maryland said the findings of the study not only changed understanding of how life is maintained on Earth, but could also change life on other planets.
“water considered essential for life to be able to flourish,” she said.
“So, if we’re looking at the universe and we find all these exoplanets, we start looking at which of these planetary systems might be potential hosts for life.
“In order to be able to understand these other solar systems, we want to understand our own.”
How did this discovery come about?
Professor Newcombe’s team analyzed melted meteorites that were floating in space 4.5 billion years ago.
Some come from the inner solar system, where the Earth is, where conditions are generally thought to be warm and dry, while others come from the colder, icier outer rim.
Because they only recently fell to Earth, this is the first time their atomic makeup — including the amount of magnesium, iron, calcium and silicon — has been measured.
However, analyzing water content is particularly difficult. This is because any water on the surface of the sample or entering the interior of the device may be detected and contaminate the results.
To reduce this potential contamination, molten meteorite samples were placed under a “turbo pump” (or low-temperature vacuum oven) for over a month.
The team found that water made up less than two parts per million of their mass.
“Once the meteorite melts, there’s no water left,” said study co-author Sune Nielsen.
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What do these findings mean?
Objects from the outer solar system had been hypothesized to be rich in water given the conditions.
As such, they are considered a key component of the water that makes up 71% of the Earth’s surface.
Professor Newcombe’s team concluded that water was likely transported to Earth by unmelted meteorites.An example is Winchcombe Meteoritewhich falls in the Gloucestershire town in 2021.
The study found that the rocks that fell on Winchcombe, made up of a type of rock called a carbonaceous chondrite, contained about 11 percent extraterrestrial water (by weight), most of which was locked in minerals that exist between fluids and water. Formed during a chemical reaction between rocks on its parent asteroid, according to the Natural History Museum.
Research on the melted meteorite has been published in the journal Nature.