London News & Search
Scientists have come a step closer to proving life on other planets exists after discovering “substantial amounts of water” in another solar system.
The discovery by the Hubble Space Telescope increases the chances of life evolving on three potentially-habitable Earth-sized planets orbiting Trappist-1, a dwarf star 40 light years from the sun.
Previously it was not known how much water the planets contained.
Astronomers say the planets orbit in the star’s “habitable zone” where temperatures are mild enough to permit bodies of surface water such as lakes and oceans.
A total of seven planets similar in size to Earth are believed to circle the cool star.
The new research, published in the Astronomical Journal, suggests that the outer planets in the system still harbour large quantities of water, despite powerful radiation from the star leading to enormous levels of water loss.
Dr Amaury Triaud, a member of the international team from the University of Birmingham, said: “Hubble’s observations are of great significance, since they inform us on the irradiative environment of the Trappist-1 planets, notably on whether they can remain habitable for billions of years, like Earth has.
“However, some of our conclusions about the habitability of Trappist-1’s seven are somewhat dampened by our fuzzy knowledge about the masses of the planets. Crucial observations, able to refine the planetary masses, are being obtained as we write.”
Ultraviolet radiation from a star can cause planets to dry out through a process called disassociation which causes water molecules to break up.
The astronomers studied levels of UV radiation emitted by Trappist-1 which suggest its inner planets could have lost 20 times more water in the last eight billion years than all the Earth’s oceans combined.
But the system’s outer planets – including the three in the habitable zone – may have lost less than three Earth-oceans worth of water. This means the planets could have retained “substantial” amounts of water on their surfaces, said the scientists.
Additional reporting by Press Association.
London News & Search