Water is essential to life as we know it. However, there is still much discussion over how it got to our planet and if distant stony worlds may receive water through the same method. The James Webb Space Telescope has uncovered a discovery that may help scientists.

The discovery was made in the PDS 70 planetary system, which is approximately 370 light-years away. The system’s star is home to an inner and outer disc of gas and dust separated by an 8 billion-kilometer gap. Two gas-giant planets live in that space.


Webb’s new investigations have identified water vapour in the system’s inner disc at distances of less than 160 million kilometres from the star. This is the area where rocky, terrestrial planets may originate. Our planet is approximately 152 million kilometres from the Sun. According to NASA, this is the first time water has been identified in the “terrestrial region” of a disc that already supports two or more early planets.

The next question is determining how the water vapour arrived at the location—there are two conceivable situations. One possibility is that water molecules originate in the region as hydrogen and oxygen atoms mix. The second idea is that ice-coated dust particles are carried from the cool outer disc to the warm inner disc, where water evaporates.

Another mystery raised by the discovery is how water molecules can exist so near to the star. The star’s powerful UV radiations should, in principle, rip apart water molecules. The most plausible explanation is that the surrounding material, such as dust, acts as a protective shield for the vapour, allowing it to survive destruction. On Monday, the study was published in the journal Nature.

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