The James Webb space telescope has captured data that could help us better understand how Earth formed billions of years ago. According to the new data, James Webb has detected water vapor in planet-forming disks, which adds more credence to a long-standing theory on how planets like Earth are formed.
Webb detected the water vapor in two different compact disks of gas and dust, which surround two different starts – both of which are between two and three million years old. That’s actually pretty young in the grand scheme of our universe’s timeline. The two disks are located within the Taurus star-forming region, which rests roughly 430 light-years away from Earth.
The discovery of water vapor within these disks has led scientists to further theorize that planets form as part of a system known as “pebble accretion.” Essentially, small chunks of rock that are coated in ice experience friction from the gas within planetary-forming disks. This friction robs the pebbles of orbital energy, causing them to migrate inward, eventually forming together.
This discovery lends additional support to the idea that the Earth and other planets formed thanks to this pebble accretion, with tiny particles eventually coming together and amazing into the massive planets that we are now busy living on and exploring. The entire process relies heavily on the smaller pebbles joining together to create protoplanets, which then pull even more pebbles and pieces together thanks to their higher gravity.
Getting a keen understanding of how Earth formed, as well as how other worlds formed, has been an astronomical goal for decades, and while we have had multiple theories for how that has happened, including theories on how the Moon formed from a collision between Earth and another planet, we haven’t found much hard evidence until now.
The presence of water vapor within the two planetary disks that James Webb observed is a smoking gun, if you will, that helps give more credit to the theory of pebble accretion and could help us better understand how other worlds out there formed, too. It might also explain if Jupiter ate other planets to become so big.