Water has been found for the first time in the inner part of a protoplanetary cloud, the region where rocky planets like our own are formed. Water may have once been found in the same way on the young Earth.
Water is the basis of life on our planet, but it is still not clear exactly where it came from. According to some versions, it was brought by celestial bodies that actively bombarded the young Earth. According to others, it appeared in the process of chemical reactions occurring directly on it, or contained in the composition of the substance from which the planet was formed. The latter hypothesis is indirectly supported by new observations of the James Webb Space Telescope, which is described in an article in the journal Nature.
James Webb considered the system PDS 70, located in 370 light years. At its center is a young star of spectral class K: an orange dwarf slightly smaller and cooler than the Sun. It is exceptionally young - PDS 70 is estimated to be only 5.4 million years old - and is surrounded by a protoplanetary disk of gas and dust. There is a wide gap in the disk where two young planets have previously been observed. New observations in the mid-infrared showed that in the inner part of the disk, at a distance of less than 160 million kilometers from the star, there is water vapor.
Recall that over time, the cloud revolving around the star differentiates: lighter substances are mainly on the periphery, and they form gas giants, while denser ones remain closer to the center, leading to the formation of rocky planets. Our Earth is 150 million kilometers from the Sun. Thus, the James Webb telescope detected water exactly in the area where Earth-type planets are possible. According to scientists, this is the first such finding. Moreover, some models predicted that this is impossible, as water is not able to persist for long in such proximity to the star.
So far in the system PDS 70 unknown planets formed in the inner part of the protoplanetary disk, although the material for this in it is quite enough, including silicates. And if new rocky worlds are really born there, they are quite capable of including water in their composition. The authors of the paper believe that such a mechanism could have worked for the young Earth. Shielding by dust particles helped water molecules to be preserved from disintegration under the influence of the harsh ultraviolet radiation of the star, and then be part of the newborn planet.
