Scientists have discovered that a region just outside Jupiter’s orbit may have acted like a giant “planet factory” in the early solar system, producing several different types of asteroid building blocks over millions of years.
The new research, led by scientists at the Max Planck Institute for Solar System Research, was published in The Astrophysical Journal.
Using advanced computer simulations, the researchers found that the same ring-shaped region beyond Jupiter could have formed at least six different groups of meteorite parent bodies at different times.
About 4.6 billion years ago, the young sun was surrounded by a huge disk of gas and dust.
Over time, tiny dust particles collided and stuck together, gradually forming larger objects called planetesimals.
Some of these objects eventually became planets, while others remained smaller and later broke apart into today’s asteroids and meteorites.
Scientists have long suspected that not every part of the early solar system was equally good at forming planetesimals. The new study suggests that the area just outside Jupiter’s orbit was especially important.
By the time this process was happening, Jupiter had already become enormous and had cleared a gap in the surrounding disk of gas and dust. This created a high-pressure ring just outside the planet’s orbit. Dust drifting through the solar system became trapped there, forming dense collections of pebble-sized particles.
Researchers describe this region as a “dust trap.” Earlier studies showed that dust traps could help create planetesimals very early in solar system history, but scientists did not know whether the same region could later produce bodies with very different compositions.
The new simulations show that it could.
The team focused on a period between about two and four million years after the solar system formed. During that time, different materials moved through the disk in different ways. Fine, fragile dust traveled differently from larger, more stable clumps that had formed earlier under intense heat.
Jupiter acted as a barrier that blocked larger particles more effectively than smaller dust grains. Over time, this caused different mixtures of material to build up in the dust trap beyond Jupiter.
As conditions changed, new generations of planetesimals formed with very different compositions. Some were made mostly of fragile, crumbly material, while others contained much more stable material.
The researchers found that their computer models closely matched the ages and compositions of six groups of carbon-rich meteorites known as carbonaceous chondrites. These meteorites are among the oldest and most primitive rocks ever found and are believed to preserve material from the birth of the solar system.
Some carbonaceous chondrites are soft and fragile, while others contain larger visible inclusions and are more solid. The new study successfully reproduced these differences for the first time using detailed simulations of the early solar system.
Scientists say the findings strengthen the idea that dust traps played a major role in building planets and asteroids. The work also suggests that many other types of meteorites may have formed in the same region long ago, helping researchers better understand how the solar system took shape.
Source: KSR.
