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Sasselov: Planets ‘Like Earth’ in Kepler Data

Dimitar Sasselov, a co-investigator on the Kepler mission, said in a TED Talk just posted that Kepler had uncovered numerous terrestrial planet candidates in its early data. Have a look at the video below (around the 8-minute mark). “Small planets dominate the picture,” says Sasselov, showing a chart of planet candidates. A great deal of work has to go into confirming these results, but Sasselov goes on to say “The statistical result is loud and clear, and the statistical result is that planets like our own Earth are out there. Our Milky Way galaxy is rich in these kinds of planets.” How many will be confirmed, and how many shown to be habitable? Much work ahead.


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  • philw1776 July 22, 2010, 17:03

    There’s an inappropriate name for this kind of tease. I for one am sorry that the initial data embargo for Kepler got extended, but at least it didn’t get extended for the several years as mission participants wished. The sooner an army of scientists each with their own innovative approaches gets access to this data the better. PIs certainly do deserve 1st dibs, but 6 months or so seems to be a reasonable lead time for insiders to publishing papers.

    I’m also not at all sure that everyone means the same thing by “planets like our own Earth”. Lots of wiggle room there. Hints. Tease.

  • Adam July 22, 2010, 18:15

    Does slow down the science by the PIs holding stuff back, especially the bulk statistics kind of work – though that might be what they’re working on. Many hands make Light Work!

  • Carl Keller July 22, 2010, 18:31

    The name of Giordano Bruno came up in the first three minutes. One of the first men to conceptualize the stars as suns was burned at the stake as a result of the Roman Inquisition: http://en.wikipedia.org/wiki/Giordano_Bruno

    His statue in the link dignifies him as a member of his Order with his tome, wearing an expression of deep thought.

  • kurt9 July 22, 2010, 18:31

    That Kepler has found many candidates for “Earth-like” planets is not surprising to anyone. I would have been surprised by the opposite result. The presence of a free Oxygen atmosphere on any of those candidates would suggest photosynthetic activity. However, Kepler is not designed to make this determination. This will require a follow-on mission like the TPF.

  • Denver July 22, 2010, 18:47

    Gad, if only we knew what he meant by “small”.

  • Mike July 22, 2010, 19:10

    Some days ya need the patience of Job!

  • Greg July 22, 2010, 21:50

    they’ll find the shortest period planets first, right? and kepler’s not looking at any red dwarfs so they’re unlikely to find any habitable planets in the first batch.

  • Matt Robare July 22, 2010, 23:25

    This is possibly the most extraordinary news of my lifetime. I felt the world change.

  • philw1776 July 23, 2010, 8:20

    From Kepler Mission “The Kepler Mission performs an unbiased search for all orbital periods less than two years, that is, out to a Martian orbit, and for all spectral types of stars.” So M stars are imaged. In more detail, many M stars are excluded because of variability. And most Ms are too faint to be candidates. But early Ms that are stable are candidates.

  • Scott G July 23, 2010, 10:28

    Just looking at the actual sizes of the planets in our own solar system relative to one another (shown here: http://www.livephysics.com/simulations/astronomy/scale-of-the-solar-system.html ), two things stand out to me. (1) it’s obvious why terrestrial planets are so much more difficult to detect than gas giants like Jupiter. (2) there’s got to be A LOT of terrestrial worlds out there that we are simply overlooking now.

  • Zen Blade July 23, 2010, 11:14

    Good news. I believe Kepler has been in orbit for over a year, although I don’t know how much data they have analyzed. This would suggest that we are talking about a lot of hot earths, and perhaps a few “quasi earth-like” candidates.

  • bigdan201 July 23, 2010, 12:19

    And more great progress is made.

    When we do finally identify earth-like exoplanets – a possibility we are approaching – it will be a major event. Even if probes or colonization is at least a century out, the presence and knowledge of another world we could live on will change our entire society.

    Many people have had their minds opened to future possibilities by science fiction. The presence of another habitable world, even if not ideal, will influence almost everyones ideas and outlook. Instead of being discussed in small circles of interested people, the potential of space colonization will become a broad issue.

    Once minds are set on something, they can take concrete steps to make it happen. We’ve already made alot of definite progress in the past several years.. and as more people are drawn to this, more progress will be made.

  • Mike July 23, 2010, 12:59

    To Greg,
    About 2% of Kepler’s target stars are M-Dwarfs.And as philw1776 pointed out these 3000 or so Red Dwarf targets are mainly early sequence stars (M0-M2),as most late sequence M-Dwarfs in Kepler’s field of view are too faint for Kepler to observe.
    Is it possible that 3 transits of HZ planets around M-2 dwarfs could be detected in those first 43 days of science data? Yes,depending on what is considered a habitable zone for that kind of star,yes.
    Perhaps Kepler bagged some Earth-size planets in the HZ of M-Dwarfs in that first bath of data. We just have to wait a little longer for RV confirmations. At the very least RV can constrain the planetary mass of the candidates.
    To Matt Robare, I agree. We are luck to live in these great times.

  • Kenneth July 23, 2010, 13:13

    Now having done a broad area survey with Kepler the next step using something like TPF, Websters Cash’s New World’s Imager or a combination of smaller programs is to focus on characterizing in detail everything out to 60 Light Years from Sol/Terra. The technology already exists to do this, and we could do it for $5 Billion with detailed results available by 2020. If we can simply narrow the scope of our inquiry down, and are willing to take a structured multidisciplinary approach we should have a clear understanding of what is within 60 Light Years of Sol/Terra by 2020.

  • Bounty July 23, 2010, 13:30

    Awsome. Can’t wait for more results.

  • philw1776 July 23, 2010, 14:53

    @ Kenneth regarding $5B 60LY survey…such a survey falls within the upper end of a billionaire’s pet project. And privately funded projects somehow often cost less than govt programs. The funder can decide how much technology risk to accept. What more memorable thing to do posterity wise than to discover and name the more interesting HZ planets?

  • Dave Bowman July 23, 2010, 18:48

    Perhaps Kepler’s success will revitalize the TESS All Sky Survey for Transiting Planets mission. Hopefully the TESS team can turn the lemon of not being selected to fly by NASA into lemonade by using Moore’s law to upgrade their detectors and data storage.

  • spaceman July 26, 2010, 4:34

    What is so amazing about Sasselov’s “tease” is that nature permits him to say to make it: even within 50 day orbital periods, so many Earth-sized planets exist! Remember, Earth has an orbital period of 365 days. So, 43/365 equals roughly .12. This implies that Kepler scientists can already tentatively say that with 12 percent of the Earth to Sun distance around other galactic stars, there are many Earth-sized planets.

  • yeti101 July 26, 2010, 9:43

    ok im confused.

    he’s really vague in the presentation. He comes out with this “100 million” figure but does he mean for all the stars in the galaxy ? if so thats quite disapointing anyone remember this prediction http://news.bbc.co.uk/1/hi/sci/tech/2078507.stm 30 billion earths.

    But he then says they expect to find 60 earth size planets capable of supporting life. Again he doesnt say if this is just for G type or for M stars too. If its for all stars then its quite disapointing really. That would give them 5-10 “earths” around G type stars they were hoping for at least 50.

    if anyone can shed any light i would appreciate it.

  • Administrator July 26, 2010, 9:58

    Sasselov was talking about Kepler candidates and his figures are so preliminary that it’s impossible to tell how they will fit into the final Kepler tally. I notice that the Kepler team is backing away from weekend stories that ran about his presentation, emphasizing the word ‘candidates’ for these planets — I thought he made this point in his talk, but probably not clearly enough. Larry Klaes just passed this along about reaction to Sasselov:


  • andy July 26, 2010, 14:20

    I’m not entirely sure how “new” this is, certainly the arXiv papers produced at the initial data release showed that many planet candidates smaller than Neptune were being discovered. In fact, that figure shown during the talk looks very much like a re-bucketed version of the histogram in this paper.

    I guess that since the talk is more user-friendly than an arXiv paper it is all getting a load of hype now rather than back then. It is particularly amusing to see the writer at SpaceRef getting his knickers in a twist over this, despite the result being not particularly different from one that’s been available online for several months now.

  • joe cavanagh July 27, 2010, 16:31

    young people… don’t poo-poo these fascinating results. As a 60 year old, I clearly remember 30-40 years ago when we had NO idea if there was even ONE other planet outside our solar system. Now MILLIONS ?? This is historic stuff. In 100 years, when MLB has teams in GLC-234, this guy could be the new Columbus. JC

  • coolstgar July 27, 2010, 20:42

    @Mike you make a very good point that’s being ignored (on purpose?) by most (definitely including the members of the Kepler team): Kepler already should have multiple transits from planet(s) around K and M dwarfs. Of course, these will be hard or impossible (right now, next generation ground based telescopes will make this pretty easy) to confirm with RV data.
    If they DO NOT have transists of earth-sized planets around K & M dwarfs already, then that doesn’t bode well for what may be (could have been) great places to look for life.

  • andy July 28, 2010, 13:31

    This latest post on the Kepler blog confirms my suspicions: this talk was about the results that had already been released.

    Furthermore, these are Earth-like planets in the sense of being terrestrial planets, not Earth-like as in habitable:

    As of today none of the candidates smaller than 2 Earth radii is in the habitable zone; their orbits are too small, which is why it was easier to spot them after just 43 days. Habitable planets will take a lot more time, as Kepler needs to observe more than one transit.

  • ljk July 29, 2010, 18:51

    Kepler Mess: We Could Certainly Use Carl Sagan Right


    “This is paradigm shifting stuff. Its about confirmation of centuries of speculation and dreaming as to the nature of our world’s uniqueness and/or commonness with regard to the universe around us. Now the Kepler team is fumbling its way through clarification of what was said and was not said, implied and miscommunicated. If you are going to go out and talk about things with such an epochal potential for all humans to think about, you owe it to everyone involved (in other words everyone, everywhere) to make damn sure you know how to convey this information. If not, then find someone who can do it.”

    We Could Certainly Use Carl Sagan Right Now

  • Duane June 15, 2011, 18:12

    Very interesting. If they find super earth which I hope they will, we should send a signal to advanced ETs like, “Hello ET. Look, we’re human here because we’re primitive. We need your help to find cure against disease, help us live forever and so on.”