Scientists Have Discovered An Entire System Of Earth-Like Exoplanets
A major announcement from NASA in the search for possible life outside the Solar System.
In the latest news about the continued search for Earth-like planets outside the Solar System, NASA announced today the discovery of an entire system of Earth-like exoplanets orbiting a star just 40 light-years away:
Not just one, but seven Earth-size planets that could potentially harbor life have been identified orbiting a tiny star not too far away, offering the first realistic opportunity to search for signs of alien life outside of the solar system.
The planets orbit a dwarf star named Trappist-1, about 40 light years, or some 235 trillion miles, from Earth. That is quite close in cosmic terms, and by happy accident, the orientation of the orbits of the seven planets allows them to be studied in great detail.
One or more of the exoplanets in this new system could be at the right temperature to be awash in oceans of water, astronomers said, based on the distance of the planets from the dwarf star.
“This is the first time so many planets of this kind are found around the same star,” said Michael Gillon, an astronomer at the University of Liege in Belgium and the leader of an international team that has been observing Trappist-1.
They could even discover convincing evidence of aliens.
“I think that we have made a crucial step toward finding if there is life out there,” said Amaury H.M.J. Triaud, an astronomer at the University of Cambridge in England and another member of the research team. “Here, if life managed to thrive and releases gases similar to that we have on Earth, then we will know.”
The findings appeared Wednesday in the journal Nature.
Telescopes on the ground now and the Hubble Space Telescope in orbit will be able to discern some of the molecules in the planetary atmospheres. The James Webb Space Telescope, scheduled to launch next year, will peer at the infrared wavelengths of light, ideal for studying the dimmer light coming from Trappist-1.
Comparisons among the different conditions of the seven will also be revealing.
“The Trappist-1 planets make the search for life in the galaxy imminent,” said Sara Seager, an astronomer at the Massachusetts Institute of Technology who was not a member of the research team. “For the first time ever, we don’t have to speculate. We just have to wait and then make very careful observations and see what is in the atmospheres of the Trappist planets.”
Even if the planets all turn out to be lifeless, scientists will have learned more about what keeps life from flourishing.
Astronomers always knew other stars must have planets, but until a couple of decades ago, they had not been able to spot them. Now they have confirmed more than 3,400, according to the Open Exoplanet Catalog. (An exoplanet is a planet around a star other than the sun.)
While the Trappist planets are about the size of Earth — give or take 25 percent in diameter — the star is very different from our sun.
Trappist-1, named after a robotic telescope in the Atacama Desert of Chile that the astronomers initially used to study the star, is what astronomers call an “ultracool dwarf,” with only one-twelfth the mass of the sun and a surface temperature of 4,150 degrees Fahrenheit, much cooler than the 10,000 degrees of heat radiating from the sun. Trappist is a shortening of Transiting Planets and Planetesimals Small Telescope.
Until the last few years, scientists looking for life elsewhere in the galaxy have focused on finding Earth-size planets around sun-like stars. But it is difficult to pick out the light of a planet from the glare of a bright star. Small dim dwarfs are much easier to study.
Last year, astronomers announced the discovery of an Earth-size planet around Proxima Centauri, the closest star at 4.24 light years away. That discovery was made using a different technique that does not allow for study of the atmosphere.
Trappist-1 periodically dimmed slightly, indicating that a planet might be passing in front of the star, blocking part of the light. From the shape of the dips, the astronomers calculate the size of the planet.
Trappist-1’s light dipped so many times that the astronomers concluded, in research reported last year, that there were at least three planets around the star. Telescopes from around the world then also observed Trappist-1 as did the Spitzer Space Telescope of NASA.
All seven are very close to the dwarf star, circling more quickly than the planets in our solar system. The innermost completes an orbit in just 1.5 days. The farthest one completes an orbit in about 20 days. That makes the planetary system more like the moons of Jupiter than a larger planetary system like our solar system.
“They form a very compact system,” Dr. Gillon, of the University of Liege, said, “the planets being pulled close to each other and very close to the star.”
In addition, the orbital periods of the inner six suggest that the planets formed farther away from the star and then were all gradually pulled inward, Dr. Gillon said.
Because the planets are so close to a cool star, their surfaces could be at the right temperatures to have water flow, considered one of the essential ingredients for life.
The fourth, fifth and six planets orbit in the star’s “habitable zone,” where the planets could sport oceans. So far that is just speculation, but by measuring which wavelengths of light are blocked by the planet, scientists will be able to figure out what gases float in the atmospheres of the seven planets.
So far, they have confirmed for the two innermost planets that they are not enveloped in hydrogen. That means they are rocky like Earth, ruling out the possibility that they were mini-Neptune gas planets that are prevalent around many other stars.
Because the planets are so close to Trappist-1, they have quite likely become “gravitationally locked” to the star, always with one side of the planets facing the star, much as it is always the same side of Earth’s moon facing Earth. That would mean one side would be warmer, but an atmosphere would distribute heat, and the scientists said that would not be an insurmountable obstacle for life.
As with the previous announcements regarding Earth-like exoplanets found around other stars both near and far, it’s important to note what this announcement does not mean. So far, there is not sufficient evidence to say whether there is evidence that conditions exist on any of these planets that would make it possible for life as we know and understand it to arise in even its simplest forms. We’re also quite far away from being able to say definitively that this is evidence of any form of life, not to mention any evidence of intelligent life of any kind. Indeed, given the limitations of technology and the distance between here and there, the odds that we’d be able to definitively reach that conclusion any time soon are fairly low. What we are able to say, though, is that we’ve found further evidence that the existence of Earth-like exoplanets elsewhere in the Milky Way Galaxy establishes that our planet is not so unique as to make it impossible that life could have arisen elsewhere at some point in time, or that it hasn’t done so already. That alone is a profound conclusion because it wasn’t so long ago that we couldn’t say for sure that planetary systems resembling our Solar System were a common occurrence at all, never mind that there could be planets like Earth elsewhere in the universe. At this point, in fact, it seems as though we can say for sure that our planet isn’t unique in the galaxy and that the odds are that there are far more planets like this elsewhere, not only in our galaxy but also elsewhere in the vastness of the universe.
As noted, the next step in the process for the scientists working on these discoveries will be an attempt to determine if the conditions for life can be confirmed on any of these planets. This will come when the James Webb Telescope is launched into orbit in October 2018. This telescope will go far beyond the capabilities of the Hubble and Keppler Telescopes in that it will be able to use advanced equipment to measure light emissions from the planets to determine the composition of their atmospheres. If evidence of the gasses known to be essential to be life as we know it are found, then that will be yet further confirmation of their Earth-like status and raises the exciting potential that we’ve discovered evidence of life itself, although that will be far more difficult to determine. Ultimately, that determination could end up being as much guesswork as anything else, but it would nonetheless be a revolutionary finding that will change our ideas of just how abundant life in some form could be in the universe as a whole.
This discovery also emphasizes the importance of a point that I’ve made in the past, namely the idea that NASA and our space program is far more successful than some critics have lamented in recent years. With the retirement of the Space Shuttle and the end, for now, of America launching its own manned missions to space, many critics have claimed that NASA has lost focus and that the United States has essentially given up when it comes to having a credible space program. That claim is obviously without merit. For one thing, while we are currently reliant on Russia to get astronauts to and from the International Space Station, research and testing on a new generation of manned space vehicles by NASA and various private initiatives such as SpaceX is well underway, and it is projected that we’re only a few years away from the U.S. being able to get astronauts to the ISS on its own. Additionally, there are plans for a return to the Moon in the very near future as part of a longer-term project that has a mission to Mars as the ultimate target. Finally, while all of this is going on we have the successes of the unmanned program to point to as evidence of just how successful our space program has been over the past several years. Just in the past several years, we’ve seen fly-by missions to Pluto, Saturn, Jupiter, and the Asteroid Belt, ongoing rovers on the surface of Mars that continue to return data to Earth on a nearly daily basis, two probes (Voyager I and II) that have essentially departed the Solar System, and now these discoveries which are arguably more profound than simply launching a few guys to the International Space Station and then returning them three to six months later. That doesn’t sound like a “dead” space program to me, it sounds like to me like one that is very much alive and well and expanding human knowledge on a daily basis.
Illustration via NASA and JPL
Under relentless budget pressure, NASA has focused on planetary missions over deep space missions, and (obviously) unmanned over manned. Despite that, their recent successes have been tremendous:
* the stunningly successful New Horizons mission to Pluto
* the equally successful Dawn mission to Vesta and Ceres
* still more amazing success with Cassini/Huygens
Even more importantly, NASA earth science programs provide data worth many billions of dollars per year to the global economy, ranging from crop surveys to space weather forecasts. Most Americans are blissfully unaware of any of these NASA activities.
And NASA kicks Guillermo Gonzalez and Jay Richards in the nuts yet again.
@DrDaveT: But maybe we’ll notice their absence since Trump admin is talking about axing all earth science from NASA’s mission…
No, we won’t notice — and if anyone does notice, they won’t blame Trump, they’ll blame the TV weatherman for getting the big storm wrong, or Mexico for the high price of fruits and vegetables, or United Airlines for cooking their gonads on a polar flight, etc.
our GDP is 70% larger than china’s.
our R&D budget is 25% larger than theirs.
and theirs is growing faster than ours.
while we elect Donald Trump and put Rick Perry in charge of the Department of Energy (which oversees boucoup science funding).
@dxq: Heh, it’s been pretty obvious for a long time that intelligent designers were barking up the wrong tree when talking about habitable planets.
However, materialists still have a long ways to go to prove how amino acids naturally assemble all the way to proteins and DNA (on a reasonable timescale). Should be an interesting century ahead of us in scientific discovery, hope I get to see most of it …
I might’ve named the planets after the Seven Dwarfs but odds are they’ll find another in the system and then what would you do?
I’m surprised (and pleased) by how many other readers understood your reference.
Oh no, don’t go there with that label (wink)! I know plenty of devout Christians and Jews who approach the work on abiogenesis as a viable possibility.
That’s the nature of science – its always a long way to go. Right now the two most successful and foundational theories of physics, quantum mechanics and general relativity, are mutually contradictory. We use both because both give excellent predictions within their realm (as in nine decimal place accuracy for quantum mechanics in some experiments), but at least one and probably both are ultimately wrong.
One possibility for a theory which combines both of their realms is string theory – but physicists still have a long way to go on that one.
However, in the meantime we just pretend quantum mechanics is on the right track, and use it to develop things like computers and most of our biotechnology because its the best approximation we have. Same for the theory of evolution; its got a long way to go. But genetics and the biochem that comes with it is the best we currently have, and so we use it.
Science is never a finished product. It always has a long way to go.
@george: Trying to come up with quantum gravity is like trying to chew off your own teeth. I took a seminar course on the topic many many years ago and it was extremely, well,…..topological.
I’m only 40, and when I was a freshman in high school, exoplanets were a fascinating idea, lots of speculation and fantasy, and that’s it. Just 24 years later we know of 3,400. This star is so close that light that left it on my birthday is hitting us now. Planets so close we can creep on them. 😀
while there will always be gaps in our knowledge, those gaps shrink, sometimes rapidly.
Trappist-1. Sounds like a nice place.
I’ve been wondering where Kellyanne has been.
Could this be the kiss of death for Mouthpiece Conway?
They’re probably both special cases of a more general theory, much the same as relativity converges to Newtonian mechanics for slowly moving objects.
Well … at least now we know where we’re going in the inevitable Firefly migration that follows Trump’s presidency.
I work for a NASA mission and you would be amazed with how much we do with so little.
Missing from this story is the fact that the ‘Trappist’ telescope was named after ‘Trappist beer’ as nod to its Belgian origins. You can do science without beer, but it’s better with a brew.
@Argon: I’m currently finishing God’s Undertaker – Has Science Buried God? by John C. Lennox which was recommended by my family’s pastor. (Yeah, I got kicked out of the church, why’d you ask?)
I’d actually recommend this book if you feel like having your beliefs challenged – my understanding is this is probably the best they got. At the very least, there is a lot of interesting science from many different fields, even though the guy is trying to guide you towards ID. That said, he spends way too much time worrying about what Dawkins says. I’ve annotated the crap out of mind, but I admittedly don’t have answers for a lot of the arguments (nor does science, at this point in history).
This is great. Now Lena Dunham and Michael Reynolds have an alternative home to New Zealand.
People sometimes think Richard Dawkins is some kind of Atheist Pope. But If I were thinking about atheism, I’d concern myself with philosophers. Richard Dawkins was a good biologist, is often an excellent science communicator, but as a philosopher he’s a layman like most of the rest of us. Go to Dawkins if you want to think about biology. Go to Daniel Dennett if you want to think about atheism. He’s a serious philosopher.
Exactly. BTW, this is why I have a problem with ID proponents’ arguments about a “tuned” universe. Numbers like the strong and weak nuclear forces and gravity are just numbers that make our incomplete theories work. Just because we have to measure them, rather than being able to calculate them like pi or e, doesn’t mean they are random values. This is the ID folks usurping the arrogance they normally apply to materialists. They are assuming our theories are perfect when they look at it and say, “oh, this number has a lot of decimal places, therefore God tuned it perfectly so the universe would work right.”
@dxq: Daniel Dennett is mentioned a few times in that book. I didn’t know who he was, so I kind of skimmed over Lennox’s brief critiques. A couple soundbites isn’t going to do anybody justice, especially when the person doing the quoting intends to dismantle them.
I don’t know much about him. I consider my atheism simple and coherent and suited for me, and I simply don’t care to think about it much, or theology of any type. But the few hours i’ve watched and thought about Dennett, Dawkins, and the rest, Dennett struck me as a rigorous thinker, with careful reasoning, and so just the sort of chap to read to get informed about that stuff, should one desire.
I’m much more concerned with someone’s values, than whatever metaphysical speculations they favor. Good values matter a lot more than theological labels, it seems to me.
1) Does this have something to with exoplanets?
2) Ain’t no way I’m clicking on something called Zero Hedge!
3) James O’Keefe, professional and convicted liar, enough said.
@Franklin: Some time ago NASA confirmed the existence of the Planet X (also known as Nibiru), which astronomers and other people had known about for a long time. Planet X is closer to Earth than the new planets in this article, and may possibly be in the Solar system at this time. It is not noticed as easily because it is not in the same orbital plane as the other planets. It could be the possible explanation for some of the recent conditions that have been occurring here on Earth: volcanic and earthquake activity, weather anomalies and abnormalities, strange animal behavior, increased magnetic field fluctuations, and increases in radiation levels in certain locations. How close this planet will actually get to Earth is still being analyzed.
See: Popular Science, Space Weather, BP Earthwatch
I never went down that rabbit hole in my studies (a fourth year course in string theory was enough to convince me my future lay elsewhere – Edward Witten I’m not), but back in the day some of my fellow grad students, folks both considerably smarter and much more masochistic than I am, went that route, either via string theory or loop quantum gravity, and from what they tell me they’re often one short step from being straight jacket material.
If your field is related to that you have my deepest respect. And my condolences.
i’m not an astronomer, but I don’t think this is true.
@teve tory: Yeah, I’ve only seen increases in confidence levels based on indirect evidence. The word ‘confirm’ would suggest something a bit more direct.
@teve tory: Yeah, I’ve only seen increases in confidence levels based on indirect evidence. The word ‘confirm’ would suggest something a bit more direct.
Sorry, Tyrell, but blaming irregular weather on Planet X, while conceivable, seems like an attempt to ignore the evidence in front of our faces.
I agree in the sense that you can’t really talk about free will or dualism without knowing all of Dennett’s arguments, because he’s the spear-carrier for modern materialist philosophy. But that said, his arguments are… badly flawed. Usually either by being circular, or (even worse) by being of the form “Free will is obviously nonsensical as usually defined, but if we use “free will” to refer to the illusion of having free will, then we can say that free will exists. So there’s no incompatibility between free will and determinism.”
Dennett’s the sort of clever idiot who really believes that people ought not believe in free will because determinism is true — as if people have any ability to choose what to believe if there’s no free will…
I think I still own a copy of the The Mind’s I somewhere, but it’s badly dented from all the times I threw it against the wall.
I wonder about the depictions of ocean on one side and ice on the other for these gravity locked planets. Nearly all the water on such a planet would accumulate on the dark side, as once there it’s only going back to the warm side at a glacial pace. Every bit of evaporated moisture that was blown over that side would fall as snow or ice pellets, and it’s hard to imagine such a vast temp difference not generating a lot of airflow between the sides.
Huh. Apparently the Forever War will be started by the Trappans, not the Taurans.
Still not looking forward to the Ration Wars of 2007, though.
Everyone seems to forget pi is a value of a circle divided against itself.
@george: Heh. My boyfriend-at-the-time was at the Institute for Advanced Studies and working with Ed Witten. He finally got fed up with string theory, professed it all “mental masturbation”, and fled academia entirely to become an (extremely successful) entrepreneur.
I still have a very soft spot in my heart for him. If he hadn’t been my boyfriend at the time I probably would have never learned how to do real research in physics–nor how to stick with it until you got something. (My advisor was about as useful as the proverbial tits on a bull and had the corresponding temperament.)
I did my own scampering-away-from-physics-academia after realizing that even the experimental solid-state physicists were having difficulty finding jobs, bounced around different professions, and will probably end up back purely as an entrepreneur once my company ramps up enough.
Also keep an eye out for the Enterprise-in-Space project, guys. (Yeah, my company is involved.)
P.S. If anyone wants to really blow his mind, go read Julian Jaynes “Consciousness as the Breakdown of the Bicameral Mind.”
@Lit3Bolt: Sorry, I’m not even sure what you’re getting at here.
Link bookmarked, looks like it could be interesting. Are you working for the company as a researcher, or as an entrepreneur?
I’d be tempted to call string theory mental masturbation too, except I know a big part of my criticism would be based on my realization that its beyond me (blush). So I console myself by calling it applied math, and so not really relevant (however interesting it is) to an experimentalist. I moved away from physics research as well, sliding into electrical engineering (lots of interesting and well paying jobs there, including in academia). Its a pretty easy transition for a physicist, either at grad school level, or more commonly in the workplace itself.
I feel your pain regarding old supervisors. I’ve had both good and bad; the good ones are rare but make you understand why a mentoring system can work. The bad ones are more common and make you consider homicide (possibly even get away with it if you can stack a jury with ex-grad students). The funny thing is that as a prof in the sciences, unless you’re famous enough to get huge research grants, you depend upon grad students to run your lab (the cheapest, hardest working labor you can get, tho sadly by the time they’re completely up to speed they’re more or less moving on); that should be enough incentive to treat your students well, but strangely enough it often isn’t.
@george: Heh, no it’s my own little company. (If you need materials analysis done on the nanoscale…) I got dragged into the EIS project because the person running it is an old friend of mine and contrary to all my protestations that nanotechnology and gravity are totally incommunicado (making it really really hard to design nanotech experiments that differ according to whether they’re done in 1g or 10^-4g) they insisted on plunking me in. (I actually do have a background in space development as well from my time in Japan.)
When you get a good advisor, he can be fantastic. I had Millie Dresselhaus as my undergrad thesis advisor and probably wouldn’t have ended up in the nanotech area except for her. Wonderful lady!
@Franklin: The main stream “news” media ignores these news events: huge, mass animal deaths and strange animal behaviors; increase in volcanic and earthquake activity (Oklahoma !); snowstorm in the Arabian desert; high radiation levels in Europe; strange fireballs and lights seen in skies everywhere; southeast US sees February heat wave with plants sprouting; and why are so many world leaders visiting Antarctica ?
Go to alternative news sources. Do not be caught asleep.