First water detected on potentially 'habitable' planet

First water detected on potentially 'habitable' planet
This artist's impression shows the planet K2-18b, its host star and an accompanying planet in this system. K2-18b is now the only super-Earth exoplanet known to host both water and temperatures that could support life. UCL researchers used archive data from 2016 and 2017 captured by the NASA/ESA Hubble Space Telescope and developed open-source algorithms to analyse the starlight filtered through K2-18b's atmosphere. The results revealed the molecular signature of water vapour, also indicating the presence of hydrogen and helium in the planet's atmosphere. Credit: Credit: ESA/Hubble, M. Kornmesser

K2-18b, which is eight times the mass of Earth, is now the only planet orbiting a star outside the Solar System, or 'exoplanet', known to have both water and temperatures that could support life.

The discovery, published today in Nature Astronomy, is the first successful atmospheric detection for an exoplanet orbiting in its star's '', at a distance where water can exist in liquid form.

First author, Dr. Angelos Tsiaras (UCL Centre for Space Exochemistry Data (CSED)), said: "Finding water in a potentially habitable world other than Earth is incredibly exciting. K2-18b is not 'Earth 2.0' as it is significantly heavier and has a different atmospheric composition. However, it brings us closer to answering the fundamental question: Is the Earth unique?"

The team used archive data from 2016 and 2017 captured by the ESA/NASA Hubble Space Telescope and developed open-source algorithms to analyse the starlight filtered through K2-18b's atmosphere. The results revealed the molecular signature of water vapour, also indicating the presence of hydrogen and helium in the planet's atmosphere.

The authors believe that other molecules including nitrogen and methane may be present but, with current observations, they remain undetectable. Further studies are required to estimate cloud coverage and the percentage of atmospheric water present.

This artist's impression shows the planet K2-18b, its host star and an accompanying planet in this system. K2-18b is now the only super-Earth exoplanet known to host both water and temperatures that could support life. UCL researchers used archive data from 2016 and 2017 captured by the NASA/ESA Hubble Space Telescope and developed open-source algorithms to analyse the starlight filtered through K2-18b's atmosphere. The results revealed the molecular signature of water vapour, also indicating the presence of hydrogen and helium in the planet's atmosphere. Credit: ESA/Hubble, M. Kornmesser

The planet orbits the cool dwarf star K2-18, which is about 110 from Earth in the Leo constellation. Given the high level of activity of its red dwarf star, K2-18b may be more hostile than Earth and is likely to be exposed to more radiation.

K2-18b was discovered in 2015 and is one of hundreds of super-Earths— with a mass between Earth and Neptune—found by NASA's Kepler spacecraft. NASA's TESS mission is expected to detect hundreds more super-Earths in the coming years.

Co-author Dr. Ingo Waldmann (UCL CSED), said: "With so many new super-Earths expected to be found over the next couple of decades, it is likely that this is the first discovery of many potentially habitable planets. This is not only because super-Earths like K2-18b are the most common planets in our Galaxy, but also because red dwarfs—stars smaller than our Sun—are the most common stars."

The next generation of telescopes, including the NASA/ESA/CSA James Webb Space Telescope and ESA's ARIEL mission, will be able to characterise atmospheres in more detail as they will carry more advanced instruments. ARIEL is expected to launch in 2028, and will observe 1,000 planets in detail to get a truly representative picture of what they are like.

Professor Giovanna Tinetti (UCL CSED), co-author and Principal Investigator for ARIEL, said: "Our discovery makes K2-18 b one of the most interesting targets for future study. Over 4,000 exoplanets have been detected but we don't know much about their composition and nature. By observing a large sample of planets, we hope to reveal secrets about their chemistry, formation and evolution."

"This study contributes to our understanding of habitable worlds beyond our Solar System and marks a new era in exoplanet research, crucial to ultimately place the Earth, our only home, into the greater picture of the Cosmos," said Dr. Tsiaras.

Secretary of State Andrea Leadsom said: "Space exploration is one of the greatest adventures of our time, and for decades, scientists and astronomers have scoured the skies for planets capable of supporting life. This discovery by UK researchers is a giant leap forward in this endeavour, opening a new world of possibilities. The secrets of our universe are out there, and I am enormously proud that our Government-backed researchers and councils are at the forefront of efforts to unlock answers to mysteries that have endured for centuries."

Chris Lee, the UK Space Agency's Chief Scientist, said: "This exciting discovery demonstrates the UK's leading strengths in the science of exoplanets. "We continue to build on this expertise, with UCL at the heart of a new mission—ARIEL—to study the atmosphere of worlds orbiting other stars in our Galaxy. This is one of a number of international space science missions involving leading roles for UK science and industry and forms part of our ongoing commitment to the European Space Agency."

Dr. Colin Vincent, Head of STFC's Astronomy Division, said: "Finding other planets that might have the capability to support life is one of the holy grails of astronomy research. This result based on data from the Hubble Space Telescope gives an exciting taste of what may be possible in the next few years as a number of new telescopes and space missions supported by STFC and the UK Space Agency come online."


Explore further

Astronomers determine earth's fingerprint in hopes of finding habitable planets beyond the solar system

More information: Angelos Tsiaras, Ingo P. Waldmann, Giovanna Tinetti, Jonathan Tennyson & Sergey N. Yurchenko, 'Water vapour in the atmosphere of the habitable-zone eight Earth-mass planet K2-18 b' Nature Astronomy (2019). DOI: 10.1038/s41550-019-0878-9
Journal information: Nature Astronomy

Citation: First water detected on potentially 'habitable' planet (2019, September 11) retrieved 18 September 2019 from https://phys.org/news/2019-09-potentially-habitable-planet.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
3529 shares

Feedback to editors

User comments

Sep 11, 2019
Stunning! In my lifetime we have gone from not only not knowing whether there were planets around other stars, to being able to detect them with various methods, to sampling their atmospheres. All since '92!
Now, get us a telescope that can detect O3, and pollutants, and then...............................!

Sep 11, 2019
This is so stupid. A planet twice the size of ours could not possibly be habitable, the gravity would crush us and atmosphere would smother us! This is pure snake oil swindle!

Sep 11, 2019
This is so stupid. A planet twice the size of ours could not possibly be habitable, the gravity would crush us and atmosphere would smother us! This is pure snake oil swindle!
Perhaps your confusion is based on a faulty definition of 'habitable'. Here's is an example that might help:
the frigid Arctic is not habitable for amphibians and reptiles—or for humans, either, for that matter --Merriam-Webster online
It   i s   habitable for numerous sea creatures, of course; and an aqueous environment leaves gravity and atmospheric pressure irrelevant for animals evolved and adapted to it.

Sep 11, 2019
This is so stupid. A planet twice the size of ours could not possibly be habitable, the gravity would crush us and atmosphere would smother us! This is pure snake oil swindle!


Such an emotional reaction, pretty much highlights the state of modern discourse and exchanging of ideas in today's world. Be skeptical but calm down, and try not to let even snake oil blind you with the need to react.

The absolute pressure at one of the deep end of the great lakes is 3.7 MPa about 36 atmospheres. Plenty of critters down there, and that's not even an extreme example of life surviving in a different environments than yourself.

Sep 11, 2019
This is so stupid. A planet twice the size of ours could not possibly be habitable, the gravity would crush us and atmosphere would smother us!

"Habitable" just means potentially life supporting. It says nothing about whether earth-humans could live there. That's just something someone uneducated in the sciences would read into it.

A good guideline to scientific articles (and particularly scientific papers) : As soon as you interpret anything that's not explicitly stated in the article - you're 100% certain to be wrong. (Because if the interpretation were warranted the authors - who are with 100% certainty a lot smarter than you - would have stated it)

This is pure snake oil swindle!

Only because you flunked reading comprehension in school.

Sep 11, 2019
This is so stupid. A planet twice the size of ours could not possibly be habitable,


Think OCEAN (you dope).

Sep 11, 2019
Now, get us a telescope that can detect O3, and pollutants, and then...............................!

Well, as the article so clearly states, more than one are already in the works. You feckless ejit.

Sep 12, 2019
Now, get us a telescope that can detect O3, and pollutants, and then...............................!

Well, as the article so clearly states, more than one are already in the works. You feckless ejit.


Errrr, I know, sh!tforbrains. The point is, for the hard of thinking, that 03 and pollutants would almost certainly indicate an advanced civilisation. O3 alone, in sufficient quantities, would almost certainly indicate life of some description.

Sep 12, 2019
This is so stupid. A planet twice the size of ours could not possibly be habitable, the gravity would crush us and atmosphere would smother us! This is pure snake oil swindle!


Well, given a mass of ~ 8 m earth, and a radius of ~ 2.3 r earth, I get a surface gravity of ~ 3 g earth.
Test pilots regularly pull that sort of g. Anything that had evolved on that planet would have evolved to cope with that g. It is far from crushing.

Sep 12, 2019
Well, given a mass of ~ 8 m earth, and a radius of ~ 2.3 r earth, I get a surface gravity of ~ 3 g earth.
Test pilots regularly pull that sort of g. Anything that had evolved on that planet would have evolved to cope with that g. It is far from crushing.


^^^^^Actually, I forgot to square r, so the surface gravity is only ~ 1.5 x Earth's!

Sep 12, 2019
Errrr, I know, sh!tforbrains. The point is, for the hard of thinking, that 03 and pollutants would almost certainly indicate an advanced civilisation. O3 alone, in sufficient quantities, would almost certainly indicate life of some description.

LMAO.
Ejit is as ejit brays.
So, enlighten us ejit.
What is "sufficient quantities" and how would it indicate life, more specifically advanced life?

Sep 12, 2019

LMAO.
Ejit is as ejit brays.
So, enlighten us ejit.
What is "sufficient quantities" and how would it indicate life, more specifically advanced life?


Christ you are thick! O3 indicates an O2 atmosphere. In sufficient quantities it will indicate a considerable O2 atmosphere. The most likely (and possibly only, AFAIK) explanation for a thick O2 atmosphere is from a biogenic source, particularly if it is found alongside methane.
Pollutants would indicate industry. Giraffes tend not to have industry. Nor do chimps. Etc. So ,.......................................?

Sep 12, 2019
LMAO.
Ejit's been breathing too much pollutants into that empty space between its ears.
Hey ejit, perhaps you should get someone with a brain to read to you about Venus's atmosphere and its ozone layer.
BTW. What is the claim about our industries and the effect it has had on our ozone layer?
And, one more time. What is "sufficient quantities"?

Sep 12, 2019
Hey ejit, perhaps you should get someone with a brain to read to you about Venus's atmosphere and its ozone layer.
BTW. What is the claim about our industries and the effect it has had on our ozone layer?
And, one more time. What is "sufficient quantities"?


Like I said - you are as thick as pigsh!t. Go get an education. I said nothing about industries having an effect on the ozone layer, you moron. Learn to read. I said detecting pollutants. Such things as could only be caused by industry. CFCs for instance.
And you need to read the papers about Venus. As this article says; "However, as these new results highlight, the ***amount of ozone*** is crucial;

https://www.esa.i...ayer_too

And what are sufficient quantities? Quantities that would indicate an atmosphere rich in oxygen. Duh! Preferably alongside the detection of methane.

Sep 12, 2019
^^^^^^Further from the article;

Venus too, now supports this view of a modest ozone build-up by non-biological means. Its ozone layer sits at an altitude of 100 km, about four times higher in the atmosphere than Earth's and is ***a hundred to a thousand times less dense***.

Theoretical work by astrobiologists suggests that a planet's ozone concentration must be 20% of Earth's value before life should be considered as a cause.

These new results support that conclusion because Venus clearly remains below this threshold.


Sep 12, 2019
LMAO.
Ejit is stupid as ejit brays.
I knew you wouldn't get it, hence, my suggestion you find someone with a brain to 'splain it to yer.
So, we have been blamed for the depletion of the ozone layer. So, which is it, a high or low ozone level would be indicative of an advanced civilization?
You, ejit, just keep confirming that you don't have an iota of independent thought. So, all you do is ignorantly parrot whatever sensationalized story you happen upon, without even trying to understand just how slim it is.

Sep 12, 2019
LMAO.
Ejit is stupid as ejit brays.
I knew you wouldn't get it, hence, my suggestion you find someone with a brain to 'splain it to yer.
So, we have been blamed for the depletion of the ozone layer. So, which is it, a high or low ozone level would be indicative of an advanced civilization?
You, ejit, just keep confirming that you don't have an iota of independent thought. So, all you do is ignorantly parrot whatever sensationalized story you happen upon, without even trying to understand just how slim it is.


You are thick, aren't you (rhetorical)? I said nothing about the depletion of the ozone layer, you moron. I said the detection of O3 at substantial levels, is an indicator of a considerable percentage of O2. This, for the hard of thinking, is due to its formation from the splitting of 02 molecules high in the atmosphere. No 02, sod all ozone. Get it? When you've got that, you imbecile, go and get an education.

Sep 12, 2019
The point is, for the hard of thinking, that 03 and pollutants would almost certainly indicate an advanced civilisation.

Hey, ejit, please get someone with a brain to read and explain your own posts, since you obviously cannot.
The only advanced civilization, we know of, in the universe has been blamed for depleting its ozone layer. So, if we did not exist that layer would be denser. I know it's an impossibility for you, but try to imagine aliens analyzing our atmosphere. What level of ozone would indicate to them, that we exist? And, while you are at it, get someone with intelligence to explain to you the fact that scientists working on it, are still far from determining what to look for in detecting pollution from distant planets.

Sep 12, 2019

Hey, ejit, please get someone with a brain to read and explain your own posts, since you obviously cannot.
The only advanced civilization, we know of, in the universe has been blamed for depleting its ozone layer. So, if we did not exist that layer would be denser. I know it's an impossibility for you, but try to imagine aliens analyzing our atmosphere. What level of ozone would indicate to them, that we exist? And, while you are at it, get someone with intelligence to explain to you the fact that scientists working on it, are still far from determining what to look for in detecting pollution from distant planets.


You still here dumbo? What was the level of the ozone layer? What was it when it was seen to be depleted? What is it now? Figures in ppm will be fine. What would detection of the ppm rates tell an alien civilisation? Do some science, you uneducated clown.

Sep 12, 2019
Look up the definition of feckless ejit and you would find ^^^^^^^^^.
LMAO.

Sep 12, 2019
Look up the definition of feckless ejit and you would find ^^^^^^^^^.
LMAO.


Typical blowhard crank! As soon as he's asked to do some science, he runs away! Moron.

Sep 12, 2019
Do some science, you uneducated clown.

Typical, from the ejit jackass. Bray at you, that which it is incapable of.
You are the one who brayed that ozone at sufficient levels would indicate advanced life. Well, was that from science, or did you, as patently obvious, just pull it out of your ass.
Beyond amusing.

Sep 12, 2019
Do some science, you uneducated clown.

Typical, from the ejit jackass. Bray at you, that which it is incapable of.
You are the one who brayed that ozone at sufficient levels would indicate advanced life. Well, was that from science, or did you, as patently obvious, just pull it out of your ass.
Beyond amusing.


It is science you uneducated clown, and I linked you to an article that tells you about it. Learn to read.

Sep 12, 2019
You are the one who brayed that ozone at sufficient levels would indicate advanced life.


Liar.

Sep 12, 2019
The point is, for the hard of thinking, that 03 and pollutants would almost certainly indicate an advanced civilisation

Uh huh, ejit.
So, where in that article does it mention ADVANCED life?

Sep 12, 2019
Well...
Looks like the Anti/Castro show is in full peak...

Sep 12, 2019
The point is, for the hard of thinking, that 03 and pollutants would almost certainly indicate an advanced civilisation

Uh huh, ejit.
So, where in that article does it mention ADVANCED life?


Lying by omission, now! Here is what I said;

The point is, for the hard of thinking, that 03 and pollutants would almost certainly indicate an advanced civilisation. ***O3 alone, in sufficient quantities, would almost certainly indicate life of some description***.


Learn to read.

Sep 12, 2019
Well...
Looks like the Anti/Castro show is in full peak...


Lol. Takes his attention away from accusing DaSchneib of performing homosexual acts!

Sep 12, 2019
Here you go ejit. Get someone with intelligence to read and 'splain it to you.
https://phys.org/...ont.html

Sep 12, 2019
Well...
Looks like the Anti/Castro show is in full peak...


Lol. Takes his attention away from accusing DaSchneib of performing homosexual acts!

Only because, DaSchitebo has been posting as his true gay self...jimmybobber.

Sep 12, 2019
Here you go ejit. Get someone with intelligence to read and 'splain it to you.
https://phys.org/...ont.html


And which part of the paper that describes their model using stellar analogues of 100, 1000 & 10000 times the solar metallicity, are you not understanding? I think we'd notice that!

Sep 12, 2019
LMAO.
There you go again ejit, ignoring sound advice to find someone with intelligence to 'splain it to you.

What part of the following did you not understand? I knew you wouldn't notice that!
The researchers tested nine different gas mixtures, consistent with predictions for super-Earth and mini-Neptune type exoplanet atmospheres; such exoplanets are the most abundant type of planet in our Milky Way galaxy.

Sep 12, 2019
LMAO.
There you go again ejit, ignoring sound advice to find someone with intelligence to 'splain it to you.

What part of the following did you not understand? I knew you wouldn't notice that!
The researchers tested nine different gas mixtures, consistent with predictions for super-Earth and mini-Neptune type exoplanet atmospheres; such exoplanets are the most abundant type of planet in our Milky Way galaxy.


Lol. Fool. What has this got to do with stellar metallicity? Do you know the difference between a star and a planet? Need me to explain it to you?
What is the range of metallicities seen in F & G type stars? In other words, the ones we are going to be looking at most closely for possible alien life signals?

Sep 12, 2019
Alrighty ejit.
Enlighten us. Start with our Sun.

Sep 12, 2019
Alrighty ejit.
Enlighten us. Start with our Sun.


What about it? By definition its metallicity is 0. A log scale is used, so - 1.0 = 10% of the solar metallicity. 1.0 would indicate 10 x Solar metallicity. Surveys I've seen show the Sun is at the higher end of metallicity for G type stars.
And I'm not the eejit that needs educating on this! Just saying.

Sep 12, 2019
You know, I was a bit concerned that I might be insulting ejits everywhere by calling you that. Thanks for removing all doubt.
The question concerns, solar metallicity and its relevance to habitable planets. The reason I said to start with the sun...well...guess what...it's the only star for which we are certain there is a planet that supports life.
Now let us try again.
Enlighten us.

Sep 12, 2019
You know, I was a bit concerned that I might be insulting ejits everywhere by calling you that. Thanks for removing all doubt.
The question concerns, solar metallicity and its relevance to habitable planets. The reason I said to start with the sun...well...guess what...it's the only star for which we are certain there is a planet that supports life.
Now let us try again.
Enlighten us.


I just did you ignorant tosser. Get an education. The metallicity, as I explained, is defined as 0. The article you linked tests solar metallicities from 2 to 4. That is, 100 to 10 000 times that of the Sun. Because 10^0 = 1. 10^2 = 100. 10^4 = 10 000. Understand? Or do we need to go through a basic maths lesson as well? It is usually the way with cranks.

Sep 12, 2019
Oh ejit, I see baby steps are required with you.
Now, is that in anyway relevant to habitable planets?

Sep 12, 2019
Oh ejit, I see baby steps are required with you.
Now, is that in anyway relevant to habitable planets?


Jesus you are thick! Lol. Around what type of stars do you think we are most likely to find life? Particularly, advanced life? F? G? O? When you have figured that out, go look at the observed metallicities of the relevant stellar types. How hard can this be?

Sep 12, 2019
But I am thick, ejit.
So, why don't you tell me. Why F, G, O?

Sep 12, 2019
But I am thick, ejit.
So, why don't you tell me. Why F, G, O?


I didn't say F, G or O. They were just hypotheticals. I want a crank to actually do some work for once, and maybe learn a little science along the way, instead of shooting off their uneducated mouths.

Sep 12, 2019
What is the range of metallicities seen in F & G type stars? In other words, the ones we are going to be looking at most closely for possible alien life signals?

But, you did ejit.
Now try again. Why would we looking at F and G types?

Sep 12, 2019
What is the range of metallicities seen in F & G type stars? In other words, the ones we are going to be looking at most closely for possible alien life signals?

But, you did ejit.
Now try again. Why would we looking at F and G types?


What are stellar lifetimes by type?

Sep 12, 2019
Alrighty, now we are getting somewhere, ejit.

So, why don't you tell me?

Sep 12, 2019
Alrighty, now we are getting somewhere, ejit.

So, why don't you tell me?


Lol. Can't figure out how to use Google, eh? Lol. Your list of disabilities grows!

Sep 12, 2019
Wow, just as I suspected, you figured out how to use Google. Congratulations ejit.
Now, let us try again.
What is the lifetime for G types and how is that relevant to advanced / life?

Sep 12, 2019
Wow, just as I suspected, you figured out how to use Google. Congratulations ejit.
Now, let us try again.
What is the lifetime for G types and how is that relevant to advanced / life?


No, I have relevant degrees. And if you can't figure out the answer to your own question, then you have no place even talking about astrophysics!

Sep 12, 2019
Typical blowhard crank! As soon as he's asked to do some science, he runs away! Moron.

Alrighty ejit. There you get.

Sep 12, 2019
Typical blowhard crank! As soon as he's asked to do some science, he runs away! Moron.

Alrighty ejit. There you get.


And I was right! Science really isn't your thing, is it (rhetorical)? Shouting your mouth off to cover up your ignorance is more your thing. Now go away, there's a good crank.

Sep 12, 2019
Aww....ejit. Why so harsh? Yuh breaking my heart.
It couldn't be that I used your own words to confirm you, a self-aggrandizing liar, incapable of an original thought and too stupid to be even an ejit.

Now, back to the fields with you jackass. GET !

Sep 12, 2019
Aww....ejit. Why so harsh? Yuh breaking my heart.
It couldn't be that I used your own words to confirm you, a self-aggrandizing liar, incapable of an original thought and too stupid to be even an ejit.

Now, back to the fields with you jackass. GET !


See what I mean? You are the one who lied, but have to accuse me of it, as you have no scientific understanding. Just another uneducated blowhard. And what possible original thoughts have you had recently? That you understand science, despite all indications to the contrary? That anybody gives a toss about what uneducated loudmouths like you think?

Sep 14, 2019
Earth-Like Exoplanet

https://xkcd.com/2202/

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more