Today, Feb. 22, 2017, NASA announced the first known system of seven Earth-size planets around a single star. Three of these planets are firmly located in the habitable zone, the area around the parent star where a rocky planet is most likely to have liquid water.

NASA TRAPPIST-1 News Briefing (recording) For more info about the discovery, visit

This discovery sets a new record for greatest number of habitable-zone planets found around a single star outside our solar system. All of these seven planets could have liquid water – key to life as we know it – under the right atmospheric conditions, but the chances are highest with the three in the habitable zone.

At about 40 light-years (235 trillion miles) from Earth, the system of planets is relatively close to us, in the constellation Aquarius. Because they are located outside of our solar system, these planets are scientifically known as exoplanets.

We're a group of experts here to answer your questions about the discovery, NASA's Spitzer Space Telescope, and our search for life beyond Earth. Please post your questions here. We'll be online from 3-5 p.m. EST (noon-2 p.m. PST, 20:00-22:00 UTC), and will sign our answers. Ask us anything!

UPDATE (5:02 p.m. EST): That's all the time we have for today. Thanks so much for all your great questions. Get more exoplanet news as it happens from and

  • Giada Arney, astrobiologist, NASA Goddard Space Flight Center
  • Natalie Batalha, Kepler project scientist, NASA Ames Research Center
  • Sean Carey, paper co-author, manager of NASA’s Spitzer Science Center at Caltech/IPAC
  • Julien de Wit, paper co-author, astronomer, MIT
  • Michael Gillon, lead author, astronomer, University of Liège
  • Doug Hudgins, astrophysics program scientist, NASA HQ
  • Emmanuel Jehin, paper co-author, astronomer, Université de Liège
  • Nikole Lewis, astronomer, Space Telescope Science Institute
  • Farisa Morales, bilingual exoplanet scientist, NASA Jet Propulsion Laboratory
  • Sara Seager, professor of planetary science and physics, MIT
  • Mike Werner, Spitzer project scientist, JPL
  • Hannah Wakeford, exoplanet scientist, NASA Goddard Space Flight Center
  • Liz Landau, JPL media relations specialist
  • Arielle Samuelson, Exoplanet communications social media specialist
  • Stephanie L. Smith, JPL social media lead


Comments: 6134 • Responses: 60  • Date: 

mzoltek6981 karma

My question is simple... What's next? I mean I'm sure all the excitement of discovering and announcing this find is still fresh but what are the next steps involved in finding out more about this discovery? What information do you think is "discoverable" about this system in the near future?

NASAJPL6464 karma

NASA's Kepler/K2 is currently observing TRAPPIST-1! The spacecraft has been monitoring the brightness of the star since December 15, 2016 and will continue to do so until March 04, 2017. That's over 70 days of data. Scientists will be able to define the orbital period of the 7th planet. They may also be able to see a turnover (or reversal) in the transit timing variations which will allow scientists to refine the planet mass estimates. Perhaps we'll even find additional transiting planets. The raw data will be placed in the public archive immeiately after the observing campaign finishes. It should be available to community by March 6th. This is one of the many ways that scientists will be studying the TRAPPIST-1 system. - Natalie Batalha, Kepler Project Scientist

AGallagher4104278 karma

What is the protocol if you do find any signs of life on any of the exoplanets?

NASAJPL5394 karma

We do not yet have a protocol. Most likely we will make a tentative discovery, that will take longer to confirm. SS

ironburton2252 karma

If you do find signs of life will it be a top priority to inform the public?

NASAJPL4671 karma

It's part of our charter that NASA "provide for the widest practicable and appropriate dissemination of information concerning its activities and the results thereof," so, yes, we would inform the public. -- Stephanie

Here's a link to the charter:

pete2751175 karma

that was your chance to use the phrase "prime directive" in a serious way, you blew it

NASAJPL1526 karma

LOL, we don't have a "prime directive," but we do have Planetary Protection policy. It's sort of like the prime directive, but very real. Basically, we don't want to go looking for life only to find that we brought it with us from Earth. Read more here: -- Stephanie

TheJabberwok502 karma

So do you call it the prime directive internally? Please?

NASAJPL1392 karma

For me personally, inside my brain, sure. :) I guess that's very "internal." -- Stephanie

signedupjusttoask2580 karma

Literally just signed up to ask this question because I think it's interesting to think about. I also asked on Twitter, and I'm nothing if not repetitive and persistent and redundant.

In order to give context for the laypeople out there: if we had the same intelligence & instruments, what would we know about Earth if we looked from a TRAPPIST exoplanet?

EDIT: Wow, thanks to everyone for the lovely comments and to /u/Mr_Sassypants for the gold! I don't know what it does, but I do appreciate it! Is everyone's first day on Reddit this welcoming?

NASAJPL1381 karma

The next generation of space telescopes, after WFIRST and JWST, to be launched in the 2030's. would be capable of actually getting a spectrum of the Earth, separate from the sun, using an instrument called a coronagraph or a star shade. The current telescopes could measure the size of the Earth as it transits in front of the sun. However, that only happens only once per year, so you have to know when to look, or look for a long time. The latter strategy was adopted by the original Kepler Mission. Michael Werner

KlingonAdmiral2578 karma

How stable is the planet configuration of the system? Has it reached a stability over long timescales like our solar system has, or is it a relatively young system were we would expect the bodies to still coalesce into larger objects over time?

NASAJPL3243 karma

The stability of the system is still unclear, because it is a complex dynamical system, the planets' masses are not yet precisely determined, we don't know yet the orbital period of the 7th planet, and there could be more planets. More on this soon!

Blakwulf2560 karma

Great presentation everyone! When/how will you be able to determine if there are signs of an oxygen rich atmosphere?

There was a lot of speculation before the conference that you may have already detected that.

NASAJPL2766 karma

It's going to be awhile before we find an oxygen rich atmosphere. JWST launch in fall 2018, so we will have to wait to try until sometime after that. It turns out some oxygen-rich atmospheres might exist that are not created by life, so to associate oxygen will require care. I hope we will be able to find, identify, and announce in a few years! --SS

jszko1602 karma

How long would it take with current technology to get to this solar system? Assuming it's a good few hundred years, what is the next step in finding out what's going on there?

NASAJPL1463 karma

No technology yet to get to this new planetary system. Fledgling efforts, however, are underway to consider how to send tiny spacecraft to the nearest star which has one known planet. SS

NASAJPL594 karma

Right now there is no current technology that can get us to the new planetary system. That's why we will use space-based telescopes to "remotely" investigate by observing the planets from afar. To see fledgling efforts to send tiny space craft to a different star (with one known planet) see -SS

disse_1281 karma

Hello, and congratulations and thank you for this discovery! You people are doing amazing work. I have 2 questions for you.

  1. Do we know what kind of a gravity compared to Earth or Mars appears on those 3 planets that could have water in them?

  2. Can we expect to have the technology in the next 20-30 years that we could for see for sure that there would be life in those planets in form of vegetation?

NASAJPL1691 karma

To answer your second question, in order to see vegetation and any other surface features (e.g. oceans, continents), we’ll need future telescopes beyond JWST that will be able to directly image exoplanets. JWST will observe planets transiting their host stars. Transits are when the planet passes between us and its star, and from these transits, we can observe how gases in the planet’s atmosphere interact with starlight passing through the atmosphere. Unfortunately, this technique doesn’t allow us to see the surfaces of exoplanets. To do that, we’ll need farther future technology that may become available in the coming decades that will allow us to block out the star’s light and observe the planets directly. Examples of these technologies are starlight suppression tools called coronagraphs and starshades. The planets we observe directly with these starlight suppression techniques will not be spatially resolved: they will literally be single points of light, but don’t despair because we can still learn a lot from single points of light! By analyzing the spectrum of colors in these points of light, we can search for signs of interesting gases (like water vapor and gases produced by life called biosignatures), and we can look for temporal changes in the light caused by processes like planetary rotation and seasonal variations. However, the TRAPPIST-1 planets, being so close to their host star, would likely be tricky to directly observe in this way. These starlight suppression technologies fail once you get too close to the star, and so these types of observations would be extremely difficult. Other planetary systems orbiting hotter stars may be detectable with these technologies, though! And on them, we’d be able to search for things like vegetation and other interesting signs of habitability and life. –G.A.

NASAJPL1252 karma

Answer to first question: Determining the surface gravity requires knowledge of both the radius and mass. The uncertainties on the mass measurements are large, but our best guess is that the surface gravity of most of these planets is similar to that on Earth. One exception is planet f. It has the same radius as Earth but 68% the mass. That means the surface gravity will be 68% that of Earth. - Natalie Batalha

username10123576541929 karma

It has the same radius as Earth but 68% the mass. That means the surface gravity will be 68% lower than on Earth.

Wouldn't it be 32% lower than Earth's gravity or 68% of Earth's gravity?

NASAJPL927 karma

Yes! Corrected. - NB

NASAJPL306 karma

  1. Compared to Earth, and based on our preliminary planet radii and mass estimates, the planets' gravity for e, f, and g would be around 0.7g, 0.6g and 1.1g. Farisa Morales
  2. The next step is to analyze the composition of the atmospheres (if any), which will provide information on the conditions and processes taking place there (past and present). Farisa Morales

V2Hero842 karma

If life is discovered on any of these exoplanets, How long would it probably take from time of discovery to an actual announcement to the public? Would that time differ depending on the types of life found? Would it take longer to disclose sentient beings than it would to disclose microbial life?

NASAJPL920 karma

That is a great question and something that has been thought about a lot by many different organizations. There is a great article on this by SETI scientist Dr Duncan Forgan which looks at many different scenarios in the age of 24 hour news and social media - HW

Drunken_Economist596 karma

What are the most promising ways to search a planet that far away for life, assuming it is not intelligent enough to broadcast signals outward?

NASAJPL923 karma

We will look at the atmosphere for gases that do not belong--gases that might be attributed to life. We will not know if the gases are produced by microbial life or by intelligent alien species. --SS

EddieEh557 karma

Does TRAPPIST-1 itself pose any hazards to the planets like radiation or flares?

NASAJPL735 karma

TRAPPIST-1 shows one flare (eruption) every week and a strong one every 6 months. Its X ray activity is not yet very well known and could be also a thread for any life there. But if the planets have an atmosphere and magnetic field this could limit the level of high energy flux. This is still work under investigation to estimate those levels.

bash_maistora375 karma

What would be the temperatures on each of these planets and the most likely chemical compositions? Are they likely to have a magnetic field?

NASAJPL502 karma

Surface temperatures depend on the proximity to the central star but also on the composition and thickness of the planet's atmosphere. Since we do not yet know anything about the planetary atmosphere's, all we can say is how much energy a planet is receiving from the star compared to how much energy Earth receives from the Sun. However, because this planetary system is so nearby, scientists should be able to characterize the atmospheres with future instruments and observatories. That's one reason why we're so excited about this discovery. - Natalie Batalha

codesForLiving372 karma


I have few questions :

1.Given that numerous earth sized planets have already been discovered, what makes Trappist-1 system discovery different? Will it alter the way exoplanets are searched?


Even without listening in on their conversations, the aliens’ reasonably advanced technology would be known to us by its pollution.

If the aliens are sufficiently advanced, that they have mastered pollution and don't pollute, how would one know the difference?

3.How would discovery of intelligent life, affect geopolitics? Miss universe and similar contests?

4.Lastly, how did planet 9 go undetected for so long?

NASAJPL443 karma

Kepler taught us that temperate (i.e. Habitable Zone), terrestrial-sized planets are relatively common in the galaxy. The name of the game now is to find those near enough for atmospheric characterization. Of the few dozen Habitable Zone planets that have been detected to date, most are hundreds of light-years away whereas TRAPPIST-1 is just 40 light-years away. - Natalie Batalha

manachar360 karma

Any chance we could name these planets after the 7 dwarves?

NASAJPL694 karma

That would be a lovely idea.. With the TRAPPIST team, we were more considering using names of the few trappist beers ;) !


DSice16323 karma

Hey guys! Love this discovery, I got chills when I saw the headline.

My question is regarding the orbits of these planets. How exactly do yall think the planets' gravity is affecting the other planets?

If the innermost planets are tidally locked, would they get slightly disrupted by passing other planets?

Are their orbits not entirely elliptic? Could they be slightly "wavy" due to other planets' gravitational pulls?

Thanks for doing this AMA! I hope my question doesn't get lost in the masses :)

NASAJPL378 karma

So glad we can finally share the chills! The planets' gravity is affecting each other in leading to what we call transit timing variations (TTVs) which is at the basis of how we can estimate the masses of the TRAPPIST-1 planets. When planets are close together and their orbits are in a certain spacing, they interact with each other through gravity, causing the timing of their transits to change a little as the planets tug on each other. By measuring this change, we can determine the mass of the planets. By knowing precisely the size and mass of the planets, we can determine their bulk density, and geophysicists can then help us better understand their interiors.

Then next to this, there will most likely be some tidal heating and significant tides on the planets that would be water worlds!

The constraints on the orbital eccentricity of the planets are a work in progress and the amplitude of the effects described above will depend strongly on those. So let's see!

It is really just the beginning for the exploration of this system. Spitzer helped us lift the fail on its architecture, now we can initiate its characterization--the venture for the generation to come!


Revo_7277 karma

What information will you guys receive from these planets if the James Webb telescope is ready and functional?

NASAJPL516 karma

NASA's upcoming James Webb Telescope, launching in 2018, will take over with a much higher sensitivity. It will be able to detect the chemical fingerprints of water, methane, oxygen, ozone, and other components of a planet's atmosphere. Farisa Morales

NASAJPL165 karma

Whether or not the planets have an atmosphere, whether or not water vapor is in the atmosphere (indicative of a liquid water ocean), and possibly even signs of life by way of biosignature gases. We will be able to find out if the planets are similar to each other or different. --SS

cometz95244 karma

How is the habitable zone estimated for tidally locked planets? How does knowledge of this system affect theories of planetary formation?

NASAJPL331 karma

The habitable zone is estimated based on the luminosity of the star and recognizing how far away can you be from it such that water can exist in it's liquid form on the surface of a terrestrial planet like the earth. Too close and the water evaporates; too far and the water freezes solid. Thus, the habitable zone is independent of whether the planets are tidally locked or not. Farisa Morales

wintersdark220 karma

What are the primary impacts of being an earth sized world so close to a smaller, dimmer star? From the perspective of a human on the surface of such a world, I mean.

I read that all are tidally locked to the star - does that mean they'd only have habitability bands around the perimeter/twilight region?

NASAJPL277 karma

Tidal-locking: we think as long as there is an atmosphere (even a thin atmosphere like that on Mars) heat will circulate around the planet. So habitability location should extend beyond the limbs.

NASAJPL273 karma

Being close to the faint star puts the planet(s) in the habitable zone, but Red dwarf stars can be very active with coronal mass ejections for example, in addition to high doses of x-ray and UV radiation. However, a healthy atmosphere and magnetic field around the planet can help protect any life evolving on it. Farisa Morales

rocco888215 karma

Do we know the age of the system and planets?

NASAJPL267 karma

not precisely because such little stars evolve very veryvery slowly ! they live for hundreds of billions years compare to 10 billions for our own Sun... we can say that it is older than 500 million years, but it could be several billions years and even older than our own system (4,7 Gyear)

NASAJPL227 karma

No, we just know that it is probably older than 500 million years.

daaave33192 karma

Hi, and congrats on the amazing discovery! Although I'm aware we can't see the Trappist-1 star, where in the night sky would it be if we could see it?

NASAJPL226 karma

Aquarius is visible in the night sky in October. There's a nice graphic at the link below showing the position of the star in the constellation. Scroll down to the bottom of this page. Keep in mind that his particular star is too faint to be seen with the unaided eye. - Natalie Batalha, Kepler Project Scientist

liamquane163 karma

How long have NASA known about the discovery?

NASAJPL296 karma

What is really important about these types of discoveries is that they are checked by other scientists and confirmed external to the original team this is called the peer review process and has to occur before any scientific work is made public, to make sure we are giving the best information available -HW

Dudeguy96147 karma

How can a young aspiring astronomer like myself get involved in this kind of work? At my university it seems like undergrads get funneled directly into academia. What does it take to work at an institution like NASA? I've already started getting involved in research as a sophomore, and my dream research topic is exoplanets.

NASAJPL255 karma

There are many possibilities. You can log into the NASA Planet Quest site and see tools and data bases about the planets as they are discovered. Try logging into "Eyes on Exoplanets". JPL, Goddard, and other NASA centers have summer internships and lots going on in the world of exoplanets; this would be a good way for you to get some firsthand experience. Most NASA scientists like myself have PhDs but have chosen to work for NASA rather than in universities. You could start in a PhD program...possibly doing your research in direct conjunction with NASA, or working for a professor like Sara Seager who does lots of NASA-funded work on exoplanets. Following that, try for a postdoctoral position at a NASA center; many good postdocs go on to become regular NASA employees. I appreciate your interest! Michael Werner

NASAJPL137 karma

If you're interested in pursuing an internship with us at JPL, check out the listings at . Ad astra! -- Stephanie

LindyLove133 karma

For the 9-12 year olds in my class, what space futures might these kids look forward to? What will we need from their generation of kids to make these space dreams possible in the future?

NASAJPL175 karma

It's an exciting time to be a kid, and to be an explorer! If students out there are interested in joining us here at NASA, taking as much math as possible is always good. That said, it's also important to study language arts, too, so that you can communicate your discoveries and innovations. In the meantime, check out the exoplanet travel posters for inspiration about worlds we might someday visit: -- Stephanie

NASAJPL56 karma

There are potential future NASA telescopes currently under consideration that may be able to search for signs of life on Earthlike exoplanets. These missions may launch in the 2030s, so we'll need the next generation of scientists to study the data we collect from them! Two of these concepts are called LUVOIR ( and HabEx ( Maybe someday you could work on one of these missions, or a similar one! -G.A.

dubalubdub133 karma

Where can i find a video of this announcement? Seriously I can't find a video.

NASAJPL191 karma

Hi, you can see a replay of the news conference here: -ERL

68sherm130 karma

For the future of Exoplanet research, would it be more fruitful in your opinion to continue looking at different batches of stars for more planets, or would you rather we focus more closely on the planets that have already been found?

NASAJPL179 karma

Actually, we're going to do both! Certainly scientists will use tools like the Hubble Space Telescope and soon the James Webb Space Telescope ( to study the planets that have already been discovered in an effort to learn more about them. At the same time, the Kepler/K2 mission ( and soon the TESS mission ( will continue the search for new planets, particularly those in our neighborhood of the galaxy. DMH

Advocate86114 karma

So if we were to imagine earth as the planet closest to this star, how many of the other 6 planets would we have visited with satellites, rovers, manned orbits, manned landing, etc.?

I am trying to imagine how close they all are together in a way that is fun.

NASAJPL201 karma

Probably all of them! See this travel poster, artist's conception. SS

NASAJPL161 karma

All of them. They are very, very close together All are much closer to one another and to their host star than the Mars-Earth distance, for example. Michael Werner

ENDLESSfallout89 karma

When the JWST is launched, how will it be used to analyze this system? What will it be looking for, and what will it be able to tell us about these planets?

NASAJPL99 karma

We’ll want to search for signs of interesting gases in the atmospheres of these planets with JWST. A high priority gas we of course want to detect is water vapor since water is necessary for life as we know it and is a fundamental part of our definition of planetary habitability. We will need to stare at these targets for a long time with JWST to be able to collect sufficient signal from them for a chance at determining their atmospheric compositions. During transit events (when the planets pass in front of their star), gases in the planets’ atmospheres can absorb starlight, producing potentially detectable signals. These will be very difficult observations, however, and obtaining better constraints on these planets’ properties beforehand (e.g. their masses) can help disentangle the signals we obtain with JWST in the future. -G.A.

NASAJPL60 karma

JWST will be able to look at the atmospheres of these planets all the way out to the infrared looking for the carbon and oxygen-based species. This will give us better information about how thick the atmosphere is and what it is made up of, I.e. If it is condensed 100% water or carbon dioxide or something different. -NL

Saumure69 karma

Hello from Liège :D

My question is about the host star. I read that red dwarf stars are likely to eject a lot of solar particles therefore the habitability of planets around this kind of stars is less. What about trappist-1 ?

NASAJPL102 karma

The stellar winds of ultracool dwarf stars like TRAPPIST-1 are significantly fainter than for more massive red dwarfs, because their atmospheres is cooler and thus less charged. Still, habitable conditions on the planets require them to have magnetic fields to protect the atmospheres from these stellar winds. We don't know if they have. If we detect dense atmospheres, this will make planetary magnetospheres very likely.

123td123468 karma

Which one of the new discoveries is the one your team is most excited about?

NASAJPL168 karma

The 3 planets e, f and g are the so called habitable zone and are the best candidates to harbor liquid water and... maybe... life !

LiberalDaisy64 karma

How can you know that existing life are in need of liquid water? We don't know anything about extraterrestrial life, do we? Just because we breathe oxygen and are dependent on water, does that mean that all other potential life have the same criteria?

NASAJPL111 karma

Very true! We have a very Earth-centric perspective on Life and habitability. But this is the beauty of exoplanetary science. We are exploring other worlds, finding unexpected planet types (e.g., hot-Jupiter, super-Earths), planets around completely different types of stars. All this is helping us broadening our perspective on planetary systems, which was based on a century-long study of our own system. Now, let's hope exoplanetary science will provide us with a similar perspective shift on habitability and Life--in the Universe! J.d.W.

camping-coffee56 karma

In the presentation, one of the someone said that Spitzer was not originally designed to look for exoplanets and that it had to be re-engineered to do so. Assuming that the telescope stayed in space, how was this done?

NASAJPL85 karma

Observations such as those described today require precision much higher than 1%. At this level, we discovered in the initial data on exoplanets various "systematic effects" having to do with both the telescope and the instrument which made it difficult to achieve this level of performance. So the re-engineering really meant using the telescope and analyzing the data in new and different ways; this continues as we strive to achieve higher and higher precision. - M. Werner see for more information.

cybermage52 karma

Detecting exoplanets by their transit of their sun presumes that our angle of observation of their sun crosses the path of the planet's orbit. Isn't that really unlikely? Or, are all planets orbiting on parallel planes?

NASAJPL78 karma

You're correct! Using the transit technique, we can only find the planets passing in front of their star from our perspective. And as not all planets are on aligned plans, not all planets can be detected with this technique. Fortunately, other techniques exist to help us detect non-transiting planets (e.g., radial-velocity, direct-imaging, and astrometry techniques, among others). J.d.W.

BasedOnAir23 karma

Why does the lettering start at 'b'? What happened to planet 'a'? Thanks!

NASAJPL44 karma

"a" is for the star main star. We start naming companions with "b" if it is a planet, with "B" if it is another star. J.d.W.

IranRPCV20 karma

How soon are we likely to have information on the composition of the atmospheres and who will be making these observations?

NASAJPL21 karma

We are currently making observations of some of these new planets, what is important is that these results go through the proper scientific process, I.e. Detailed and backed up analysis, and then peer review for publication. As soon as that happens the results will be available for the public. Stay tuned there is a lot we will be learning from TRAPPIST-1 for years to come - HW

Profanion19 karma

Hello. Currently, Kepler spacecraft is observing TRAPPIST-1 system. How well can Kepler spacecraft detect planets around TRAPPIST-1 compared to Spitzer spacecraft? Are further discoveries expected?

Also, is TRAPPIST-1h the first "cold Earth" to be a candidate for further observations?

NASAJPL30 karma

Kepler can observe for about 80 days consecutively and will therefore provide a very important time series and information on the gravitational interactions between the plaets which cause timing variations. It is possible that there may be additional planets not seen by Spitzer in 20 days which Kepler could uncover. Kepler and Spitzer have comparable capabilities for the detection of planets around the TRAPPIST-1 system.

The Trappist planets are certainly among the first "cold Earths' to be candidates for further observations, and 1h in particularly will be the coldest.

Michael werner

NASAJPL20 karma

Kepler/K2 will be a great compliment to the observations that have been taken by Spitzer and other ground-based observatories. We expect Kepler to achieve comparable precision to Spitzer. Kepler has been monitoring TRAPPIST-1 since December. With 70 days of data, the spacecraft should see multiple transits of planet h. This will allow us to determine its orbital period. Kepler data will also be important for more tightly constraining the planet masses. - Natalie Batalha

LittleOddish9 karma

Hi guys! Amazing work. I was wondering, when a discovery like this is made, how do you name each planet? To differentiate them from each other.

NASAJPL7 karma

For the moment we are stuck with a convention. The star gets named according to the project's name (in this case Trappist-1). Then the planets follow b, c, d, etc. in order of discovery. So far there is no streamlined official process to give planets actual names--SS

snower_HS8 karma

Any ideas what the lifespan of the system's star is? Even if our technology were to advance, it would suck to arrive there only to have the sun go out.

NASAJPL12 karma

TRAPPIST-1 is a an ultracool dwarf star, the longest-lived stars of the Universe. It's lifetime should be much larger than 100 billions years. M. Gillon

utvetteguy7 karma

Can Hubble take a picture of these planets?

NASAJPL13 karma

Hubble can't take images of these planets, but it can do something even better: take spectra. -- NL

dinospace6 karma

How are discoveries like this made? Is it just luck kr is there a process to discovering planets?

NASAJPL6 karma

The discovery was made with the so called "transit technique" : you stare many stars and wait a little dip of the light due to a planet passing in front of it ! The discovery was made using various telescopes using that technique, first the Liege University small TRAPPIST robotic telescope but many other like the VLT, UKIRT in Hawaii and more recently the NASA IR Spitzer space telescope that was looking at TRAPPIST-1 for 20 days continuously to unravel a total of 7 earth sized planets ! There are other techniques but this one is beautiful because it gives lot of informations like the size of the planet and even the mass in this case thanks to the variation of the transit timings due to the interaction between the planets themselves

liamquane6 karma

How does the telescope work? What do you actually see? Is it just a series of numbers on a screen which you interpret into a tangible image?

NASAJPL15 karma

The Spitzer telescope points at the Trappist star. The light from the star is imaged on to what is called an infrared array, a specialized and expensive version of your cell phone camera which works in the infrared. The electronic signals from the camera, which contain the information about the brightness of the star, are stored on Spitzer and sent back to Earth, where they are analyzed electronically to determine the brightness. This was done every two seconds for twenty days; the accumulated data was sent back every three days or so. Michael Werner

bluegrassgazer6 karma

I watched the live event, and I must say it lived up to the hype! Will the JWST be able to determine if any of these planets have an atmosphere of oxygen and nitrogen? If not, what future instrument will be able to accomplish this task?

NASAJPL4 karma

Scientists are currently trying to determine this with observations from the Hubble Space Telescope which can tell us about water absorption, there are then plans to look at the system with JWST which will give us more information about the carbon-based species that may be in the atmosphere. There is a lot more to learn - HW

Miki_el_Mikingo4 karma

Why do you name TRAPPIST-1 planets from b to h? Why did you start by planet 1b, instead of 1a? Thanks!

NASAJPL2 karma

Star is labled with a capital "A" planets skip lower case "a" and start right at "b". If we had thought about this more before it became convention, we might have thought of something better. SS

akhaleesi3 karma

Will you be collaborating with other space programs in this endeavor?

NASAJPL6 karma

Anybody can apply to use the Spitzer Space Telescope and justify the scientific investigation they want to conduct this includes the international scientific community. This is the same for the Hubble and James Webb space telescopes. In fact the Hubble Space Telescope is both a NASA and ESA Telescope and the James Webb Space Telescope is NASA, CSA, and ESA Telescope. - HW

annon_tins3 karma

From the illustrations I've seen of the planets, how do you determine how they look? Or are they just assumptions?

NASAJPL6 karma

The artistic concepts are based on available data about the planets' diameters, masses and distances from the host star. You can read more about that here: -ERL (Liz Landau)

staedtler12 karma

How big is the trappist-1 star compared to our sun?

NASAJPL2 karma

It's about 10% the size of our sun, so much smaller! -ERL