In its most recent search, NASA's James Webb satellite telescope has gathered information that may help scientists understand how the Earth formed billions of years ago. The latest findings of the space telescope discovered water vapour in planet-forming discs, backing ideas about how planets like Earth were formed.
What is pebble accretion?
The telescope discovered the water vapour in two different compact disks of gas and dust that encircle two stars that are two to three million years old. The two discs are in the Taurus star-forming area, which is around 430 light-years away from Earth.
With the discovery of water vapour within these discs, scientists now believe that planets originate as part of a "pebble accretion." Small bits of rock coated in ice are subjected to friction from the gas within planetary-forming discs. This friction depletes the orbital energy of the pebbles, leading them to move inward and eventually join together.
Planets form due to pebble accretion, expert suggest
This latest finding backs the idea that the Earth and other planets formed due to pebble accretion, with tiny particles eventually combining to become the enormous worlds we now inhabit and explore. The entire process primarily relies on smaller pebbles forming protoplanets, which pull even more pebbles and pieces together due to their increased gravity.
For decades, understanding how Earth and other worlds formed has been an astronomical goal. While we have multiple theories for how that happened, including theories on how the Moon formed from a collision between Earth and another planet, we have yet to find much hard evidence.
The existence of water vapour within the two planetary discs seen by James Webb is a fact. If research further research, this could support the theory of pebble accretion and provide insight into the formation of other worlds.
