Why the meteorites that hit Earth have less water than the asteroid bits brought back by space probes – a planetary scientist explains new research
Many of what scientists know about the early solar system comes from meteorites – ancient rocks that are transmitted across space and survival in the atmosphere of the Earth. Between meteorites, it is called one type – Carbonate – It stands out as the most primitive and provides a unique glimpse into Children of the solar system.
Carbonian cartilage is rich in water, carbon and organic compounds. It is “wet”, which means that it contains restricted water inside the minerals in the rock. Water ingredients Closed in crystal structures. Many researchers believe that these old rocks played a decisive role in Delivery of water to the early ground.
Before you reach the Earth, the rocks that are generally running through space in the name of asteroids, meteorites or comets, depending on their size and composition. If a piece of these things makes it reach the ground, it will become a “meteorite”.
From monitoring asteroids with telescopes, scientists know this Most asteroids contain water -rich combinations. Models predict Most meteorites – more than half – should be carbon. But less than 4 % of all meteorites on Earth are carbon. So why is there such a incompatibility?
In a study published in the magazine Nature Astronomy on April 14, 2025I tried and my colleagues and colleagues tried to answer an old question: Where are all carbon conditions?
Mission sample return
Scientists ’desire to study these ancient rocks prompted space missions that belong to the modern sample. NASA Osiris – Rex and Jaxa’s Hayabusa2 tasks I have turned what the researchers of the carbon -rich asteroids have known.
Meteoric found on the ground is exposed to rain, snow and plants, which can change it significantly and make the analysis more difficult. Therefore, Osiris -rex mission ventured on Beno asteroid To recover a sample unchanged. This sample allowed scientists Carbon composition examination in detail.
Likewise, the Hayabusa2 trip to Ryugu asteroid The virgin samples were presented to another, with a water -rich asteroid.
These tasks allowed together Planetary scholars like me The virgin study, fragile carbon materials of asteroids. These asteroids are a direct window in the building blocks of our solar system and the origins of life.
Carbon carbon puzzle
For a long time, scientists assumed that the Earth’s atmosphere describes carbon debris.
When the atmosphere of the Earth’s atmosphere hits, it should escape great pressure and high temperatures. Carbon cartilage tends to be weaker and more interactive than other meteorites, so these things do not stop largely.
Metrics usually begin their journey when two asteroids collide. These collisions create a set of fragments of the centennial rocks to the meter. These cosmic crumbs exceed the solar system and ultimately, to fall on the floor. When you are smaller than a meter, scientists call them a meteor.
The meteorites are very small for researchers who see them with a telescope, unless they are It is about to hit the groundAnd astronomers are lucky.
But there is another way that scientists can study this category of the population, and thus understand the reason for the presence of a meteorite such different structures.
Meteoric control networks and fire networks
Use our search team our Earth’s atmosphere as our reveals.
Most meteorites that reach the Earth are small sandy molecules, but sometimes, Corps up to a few meters in diameter. The researchers can do so About 5000 metric tons of micrometeorites Earth on the ground annually. And every year, between 4000 and 10,000 large meteorites-golf ball size or larger- Earth on the ground. this More than 20 every day.
Today, digital cameras made notes around the clock to the night sky at the practical atmosphere at reasonable prices. Low -cost and highly sensitive sensors and automatic detection programs allow researchers to monitor large sections of the night sky of bright flashes, which indicate that the meteorite strikes the atmosphere.
Research teams can be subject to actual time observations using automated-orsat PhD techniques. Student – to find invaluable information.
Our team runs two international systems: FrebonA French -led network with stations in 15 countries; and Global Fire ObservatoryThe team started by the team behind Desert Fire Ball Network In Australia. Along with other open access data sets, my colleagues and I used the paths of approximately 8,000 effects that I have noticed by 19 observation networks spread in 39 countries.
By comparing all the effects of the meteorite recorded in the Earth’s atmosphere with those that successfully reach the surface, we can determine which asteroids that produce strong shrapnel enough to survive on the trip. Or, on the contrary, we can also identify asteroids that produce weak materials that do not often appear on Earth like meteorites.
The sun bakes the rocks a lot
Surprisingly, We found it Many of the asteroids do not reach the ground. Something begins to remove weak things while the part is still in space. The carbon material, which is not very durable, is likely to be broken by thermal stress when it takes its orbit near the sun.
As the carbon orbit rotates, then away from the sun, the temperature swings Shakes are formed in their materials. This process effectively drinks and removes weak water rocks from the number of things near the Earth. Anything he left after this thermal cracking and then it should survive the atmosphere.
Only 30 % -50 % of the remaining objects survive the corridor in the atmosphere and become meteorites. The pieces of their orbits closer tend to be more durable, making them more vulnerable to survival through the Earth’s atmosphere. We call this prejudice to survive.
For decades, scientists assumed that the atmosphere of the earth alone explains the scarcity of carbon meteorites, but our work indicates that a lot of removal occurs in advance in space.
To move forward, new scientific developments can help confirm these results and identify meteorite’s books. Scientists need an improvement in Using telescopes To detect things immediately before hitting the ground. Moderate more detailed for How these things are separated in the air Researchers can also help them study.
Finally, future studies can reach better ways to determine what these gunshots are using The colors of meteorites.
This article has been republished from ConversationAn independent, non -profit news organization brings you facts and trusted analysis to help you understand our complex world. Written by: Patrick M. Chopperand Nassa
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Patrick M. Chopper is a funding from the research and innovation program on the European Union horizon for 2020 under the Mary Scoesodovska Convention, No. 945298. Patrick M. receives. Chopper is currently funding from the post -PhD program in NASA.
