Stay up to date with notifications from The Independent

Notifications can be managed in browser preferences.

Hubble discovers signs of water on newly discovered Earth-sized planets near Trappist-1

Each of the worlds orbits in the star's 'habitable zone'

Jon von Radowitz
Thursday 31 August 2017 16:04 EDT
Comments

Your support helps us to tell the story

From reproductive rights to climate change to Big Tech, The Independent is on the ground when the story is developing. Whether it's investigating the financials of Elon Musk's pro-Trump PAC or producing our latest documentary, 'The A Word', which shines a light on the American women fighting for reproductive rights, we know how important it is to parse out the facts from the messaging.

At such a critical moment in US history, we need reporters on the ground. Your donation allows us to keep sending journalists to speak to both sides of the story.

The Independent is trusted by Americans across the entire political spectrum. And unlike many other quality news outlets, we choose not to lock Americans out of our reporting and analysis with paywalls. We believe quality journalism should be available to everyone, paid for by those who can afford it.

Your support makes all the difference.

Three potentially habitable Earth-sized planets in another solar system are likely to contain substantial amounts of water, say astronomers.

The discovery by the Hubble Space Telescope increases the chances of life evolving on planets orbiting Trappist-1, a dwarf star 40 light years from the sun.

Each of the worlds orbits in the star's "habitable zone", the narrow corridor 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 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.

The research is published in the Astronomical Journal.

Press Association

Join our commenting forum

Join thought-provoking conversations, follow other Independent readers and see their replies

Comments

Thank you for registering

Please refresh the page or navigate to another page on the site to be automatically logged inPlease refresh your browser to be logged in