This hole may have served as a cosmic boundary, allowing Earth-like planets to emerge on one side, while gas giants loomed in the outer regions.

In recent years, astronomers have frequently spotted conspicuous ‘voids’ and ‘holes’ in disks around other young stars. To date, they are quite puzzling phenomena. But in a new study, researchers have found evidence that our solar system may have had such a mysterious “hole.” And that may explain the striking dichotomy between the planets in our solar system.

Hole

In the early solar system, a so-called protoplanetary disk, made up of dust and gas, revolved around the sun. A protoplanetary disk is actually a flattened disk, similar to a music record, that forms around a very young star and in which planets are born. Scientists have looked into ancient meteorites that crashed into Earth in a new study. And based on this analysis, they now suggest that the protoplanetary disk around our very young sun – some 4.567 billion years ago – was also a real hole.

asteroid belt

The researchers suspect that this hole was close to where we now find the asteroid belt — a region of the solar system roughly between the planets Mars and Jupiter.

Origin
How did this hole come about? Researchers don’t really know that. One possibility is that planet Jupiter had an influence. As the gas giant took shape, its immense gravitational pull may have pushed gas and dust out, creating an opening in the evolving disk. Another possibility has to do with winds emanating from the surface of the disk. Young planetary systems have strong magnetic fields. And when these fields interact with a rotating disk of gas and dust, they can create powerful winds that blow material out with strong gusts, leaving an empty gap in the disk.

Although the last word has not yet been said about the origin of the hole, the researchers do have an idea what this hole was used for.

Cosmic frontier

According to the team, this hole was like a cosmic boundary, preventing materials on either side of it from interacting with each other. This physical separation may have contributed to the composition of the planets in our solar system. For example, Earth-like planets were born on the inside of the hole, such as Earth and Mars. From the gas and dust on the other side, Jupiter and its neighboring gas and ice giants were then born.

dichotomy

It’s an interesting theory. For this could well explain the apparent dichotomy in our solar system. “It must have been quite difficult to bridge the gap,” said researcher Cauê Borlina. “It therefore provides evidence that the formation of our planets was limited to specific regions in the early solar system.”

Not only does the study learn more about our own solar system, it can also provide more insight into other planetary systems. “Holes are common in protoplanetary systems,” Borlina says. “And we now show that we too had one in our own solar system. This provides evidence that such holes influence the composition of planets.”