New 'super-Earth' found with water and the right temperature for life

Multimedia · User Galleries · News

This massive range stems from the fact that, with Hubble observations, researchers can only identify a water signature, the "fingerprint" observed using transit spectroscopy; they can't tell how much water is there, Giovanna Tinetti, a researcher on this study and a professor of astrophysics at UCL, said during a September 10 news conference. At the moment, one extremely important piece of information that is missing is the presence, composition and structure of their atmospheres.

As of now, the researchers have concluded that there is some quantity of water and likely hydrogen in the planet's atmosphere.

"Over 4,000 exoplanets have been detected but we don't know much about their composition and nature", said Tinetti.

The new research was published September 11 in Nature Astronomy.

A planet's atmosphere plays a vital role in shaping the conditions inside it - or on its surface, if it has one.

The primary method that we use when examining exoplanets is transit spectroscopy.

'It's orbiting a completely different star, so it doesn't look like Earth. "The atmosphere of the planet leaves a characteristic fingerprint on the light ... this is what we try to observe". Further analysis can then help us match this footprint to known elements and molecules, such as water or methane. It has never before been seen in smaller planets - until now. "This is not only because super-Earths like K2-18b are the most common planets in our Milky Way, but also because red dwarfs - stars smaller than our Sun - are the most common stars".

"This is the only planet right now that we know outside the solar system that has the correct temperature to support water, it has an atmosphere, and it has water in it, making this planet the best candidate for habitability that we know right now", lead author Angelos Tsiaras, an astronomer at University College London, said in a press conference.

Although K2-18 b flaunts some of the most Earth-like features observed in an exoplanet so far - water, habitable temperatures, and a rocky surface - the researchers point out the world is still far from Earth-like.

They made the discovery studying data captured by the Hubble Space Telescope developed by Marshall Space Flight Center in Huntsville.

That's because this 33-day orbit is right smack-bang in the middle of the star's habitable zone - not too hot that liquid water would evaporate from the surface, and not so cold that it would totally freeze.

In order for an exoplanet to be defined as habitable, there is a long list of requirements that need to be satisfied.

The watery planet is not particularly Earth-like, and it's doubtful that it has a rocky surface like that of our planet, Seager and Shaefer say. It is also necessary that the planet has an atmosphere to protect the planet from any harmful radiation coming from its host star.

Tsiaras and his team think the planet is likely a rocky "super-Earth" in possession of an atmosphere that's either very water dominant, heavily mixed with a transparent gas like nitrogen, or features significant cloud formation.

"Models are really essential for the planning, but of course in all the observations we have to be willing to accept really unexpected and new things", Schaefer says. Our data are limited to an area of the spectrum - this shows how light is broken down by wavelength - where water dominates, so other molecules can unfortunately not be confirmed.

The prospective launch of Nasa's much delayed James Webb Space Telescope (JWST) in 2021, and the European Space Agency's Ariel mission seven years later, will enable astronomers to study in detail the atmospheres of the varied worlds that have been detected so far. This will help us understand just how habitable it is.

The researchers studied Hubble data to analyze K2-18 b's transit, or its movement across its host star's face, using a technique known as transit spectroscopy.

"K2-18b is very different from anything we know", says Sara Seager, a professor of physics and planetary science at MIT not involved in the research, in an email.



Latest news

Apple in hot water because of iPhone 11
CLW says that the number has now fallen from 50 percent to 30 percent, but that still violates Chinese labour laws. By recruiting these laborers, "the factory does not need to increase the wages for all regular workers", it said .

Nigerian nationals evacuated from South Africa
Democratic Republic of Congo, Bangladesh and Ethiopia topped the list of countries where people applied for asylum or refugee status in 2018.

Control's Season Pass And Post-Launch Content Outlined
Acting at the request of the enigmatic Board, Jesse explores what lies beneath the Bureau in an effort to restore order. 505 Games and developer Remedy Entertainment announced a host of upcoming post-launch content for Control .

Sir Keir Starmer: Labour is united, we want a referendum
But 46% agreed they are "fearful" of the consequences of a no-deal Brexit while 33% disagreed and 21% answered "don't know". But a general election is extremely unlikely until at least mid-November because of Mr Johnson's suspension of Parliament.

FC Barcelona: Arda Turan sentenced to 32 months in jail after brawl
However, he failed to make a major impact at the Camp Nou and was shipped out on loan to Istanbul Basaksehir in 2018. But he announced his global retirement in 2017 after he allegedly abused a journalist on the national team's plane.

Other news