Icy pebbles may be carrying water to developing planets across the cosmos!

If a film chronicling Earth's history were in the making, asteroids would likely play the role of villains, renowned for eliminating dinosaurs and various less celebrated species. Despite currently evoking trepidation as they daringly pass close to our planet, these celestial bodies might actually be the unsung heroes responsible for the existence of life on Earth.

Scientists, exploring the origins of water on Earth and other exoplanets, may have uncovered a promising hypothesis with the assistance of the James Webb telescope. This esteemed telescope has revealed a complex cosmic supply chain involving ice-covered pebbles migrating from the outer Solar System to deliver water to developing planets nearer to their stars.

The groundbreaking revelation stems from observations of four young stars surrounded by protoplanetary disks — dense gas discs encircling newly formed stars. The JWST, penetrating through the obscuring dust and gas, examined the material composition within these disks. Two of the disks exhibited an excess of water vapour in their inner regions, aligning with the theory that icy pebbles are transporting water to the evolving planets. The absence of water vapour excess in the other two disks suggests the hydrodynamical forces are stronger, trapping the icy pebbles in their outer rings.

This finding challenges the notion that the inner and outer regions of a solar system are isolated, supporting the ice-covered pebble theory as a more plausible explanation for Earth's water origin.

Contrary to the long-standing belief that Earth's water arrived from icy comets and asteroids after its formation, this new hypothesis posits that water originated from ice-covered pebbles drifting inward from the outer Solar System. The James Webb telescope's recent breakthrough is anticipated to conclusively elucidate the source of Earth's water.

Additionally, this discovery holds significance for the quest for extraterrestrial life, suggesting that the delivery of water to planets is more common than previously believed, thereby increasing the likelihood of finding life on other planets.