NASA Found Seven Earth-Sized Planets That May Support Life

Today NASA announced that a team of scientists has confirmed seven Earth-sized exoplanets orbiting TRAPPIST-1, a star located just 39 light-years away from our Sun. The six inner planets are very likely to be rocky, are roughly the same mass as Earth, and are thought to have comparable surface temperatures to our own planet. Three of the planets may even be able to support liquid water and perhaps, life.

Image: NASA/JPL-Caltech

This discovery signifies the largest number of Earth-sized planets found and largest number of potentially habitable worlds for a single star system. Both factors will make TRAPPIST-1 immensely appealing in the ongoing search for habitable worlds and life beyond Earth.

"This is the first time that so many planets of this kind are formed around the same star," Michaël Gillon, an astronomer at the Université de Liège and a co-author on the study published today in Nature, said in a press briefing. "[The planets] form a very complex system, [since] they're all very close to each other and very close to the star, which is very reminiscent of the moons around Jupiter."

In 2016, Gillon, along with astronomers Amaury Triaud, Emmanuël Jehin and others spotted three exoplanets orbiting TRAPPIST-1, classified as an "ultracool dwarf" star because it features surface temperatures under 4,400 degrees Fahrenheit. After following up on TRAPPIST-1 using the instruments like NASA's Spitzer Telescope and the ESO's Very Large Telescope, the team found four more exoplanets in the star system. All of the potentially Earth-like worlds were spotted using the transit method, which measures dips in a star's light output as a planetary body crosses in front from our line of sight.

The news has justifiably sent space geeks into a frenzy.

"Finding several potential habitable planets per star is great news for our search for life," Lisa Kaltenegger, Director of the Carl Sagan Institute at Cornell University, told Gizmodo.

Image: NASA/JPL-Caltech

In our solar system, Earth is situated squarely in the habitable zone where liquid water can form, while two other planets — Venus and Mars — skirt the inner and outer edge, respectively. According to models, the TRAPPIST-1 system contains three planets in the habitable zone, making it the record holder for stars we know of with rocky planets that could potentially support liquid water, Kaltenegger explained.

At this point, we have more questions than answers about these exoplanets. Hopefully, the James Webb Telescope, which launches next year, and the yet-to-be-completed Extremely Large Telescope will be able to tell us more about their atmospheres. This will be critical for determining whether or not the planets really can support liquid water and life.

"If the star is active (as indicated by the X-ray flux) then [a planet in orbit] needs an ozone layer to shield its surface from the harsh UV that would sterilize the surface," Kaltenegger said. "If these planets do not have an ozone layer, life would need to shelter underground or in an ocean to survive — and/or develop strategies to shield from the UV."

Artist's rendering of the TRAPPIST-1 planetary system. (Image: NASA/JPL-Caltech)

One of the many questions from this discovery is, well, can we go there? While star system Proxima Centauri is a more sensible choice for an interstellar voyage, since it also contains a rocky, habitable-zone planet and is much closer to Earth (4.22 light years away), the opportunity to find life on multiple worlds in the TRAPPIST-1 system increases its chances of a visit someday.

"Finding many potential habitable planets around a star is definitely motivating," Kaltenegger said.

[Nature]



Comments

    Love hearing news like this, amazing discovery! Hurry up with the warp drive already!! I want to explore these worlds!!!

      At current rocket speeds it would take over 700,000 years to reach these worlds.

        Yeah, but at present reaching them isn't the goal. From here we have a very good chance of seeing the atmosphere's of these planets in spectrum. If we see the atmosphere, we can make some very good calls for possible life.

    Those orbital periods are very fast, it'll be interesting to see what weather have, I doubt there would be seasons worth mentioning.

      Four seasons in one day!

      I wonder though whether they're really a good chance for life. Wasn't there more research that suggested the main reason we're alive is because we have some giants (Jupiter, Saturn) sweeping up dangerous debris before it hits Earth? If so that would imply those Trappist planets are at risk from impacts.

        Yes the theory of gas giants knocking comet orbits has some good evidence. But the downside is that the gravity more than likely created our asteroid belt, basically "preventing" a planet formation. We are finding so many unusual systems thanks to this new data. Things we "thought" we new about accretion disks (birth places of solar systems), gas giant formation (we see many in tight orbits with the star, where we thought they couldn't form). I think it shows that its hard to come up with "other" possibilities of system formation when you only (in the past) had one system to examine. It helps to compare ;) The best part is, its only "opening" possibility for life else where, before 1977, we never would have thought life could grow near a lava vent in perpetual darkness in super heated water, and in massive quantities, to the point where there are actually good theories that suggest life "started" here and moved its way up to the surface...very cool.

        I'm given to understand that this belief about Jupiter is incorrect.

        Apparently Jupiter flings objects towards us about as often as it saves us.

          Well, that is, true, what doesn't get sucked in, but rather "nudged", has a chance of still coming our way.
          Saturn and Jupiter being the "large Hoovers" that they are, sucked up a lot of left over debris, less debris means less chance of collision, but its gravity as I mentioned above stopped a planet from forming, so, gas giants can play different roles in aiding life. Jupiter has basically had both a negative and a positive affect on our inner planets. There's a study that suggests through new modeling that it actually slung a lot of crap in towards the sun during formation (lots of comets/water etc) which helped form earth/mars etc.

            So, the idea is that Jupiter had a 'sorting' effect in the early solar system.
            I can believe that, the consensus for instance is that it seems to have sorted us an asteroid belt..

            What I'd really think was awesome is if someone had a model which was takes a cloud of an arbitrary composition and predicts likely planet distributions. Anyone have a link to a summary of the state of the art in this modelling effort?

          I hadn't read that article, and the one about Jupiter saving us was (I thought) fairly recent. Doesn't mean it's right of course. Not to mention in either case they're both just theories based on models that could be flawed.

          In either case, the new system is pretty amazing and it's just a pity none of us are likely to be alive by the time we get definitive information back about it. :(

    Great to hear.
    I'm a little confused however, in the chart the planets are all between .01 and .06 AU from the star. with 1 AU being the same distance as we are from our star and hence the goldilocks zone. How can a planet at 1-6 hundredths of that distance be in the goldilocks zone? Is it because the star is much cooler?

      Yes exactly. The star is 8% the mass and half the temperature of our own.

    I really think these agencies should make it obvious that the " artist's renderings" are pure guess work.

      True, but if you go to the source at NASA they clearly say "Artists Conception" and what they "may" look like. These photos came from there.

      Edit - The "conception" by the way is weighted ever so slightly by "known" variables, distance, heat etc. so its not total guess work to suggest the surface variables like water etc

      Last edited 23/02/17 2:11 pm

      Sadly, there are people that need such disclaimers...

        inb4 usebuy finds this article.

          haha, not to worry, Im sure he'll "cherry pick" the data to fit his "unique" version of reality. ;)

    If starshot is running within 20 years at 4%c it would be about 200 years plus 40 for returned data broadcast and a few more say 5 years for analysis.
    BRING IT ON!

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