Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

I NASA: 1284 more planets from Kepler

  1. May 8, 2016 #1

    mfb

    User Avatar
    2017 Award

    Staff: Mentor

    Source: NASA to Announce Latest Kepler Discoveries During Media Teleconference

    Livestream

    Time conversion reference: this post was posted at 7:45 pm EDT.

    My guess: various roughly Earth-sized exoplanets around dwarf stars, probably at least one in the habitable zone.

    Edit: More than 1000 more exoplanets, see post #5.
     
    Last edited: May 10, 2016
  2. jcsd
  3. May 8, 2016 #2

    ProfuselyQuarky

    User Avatar
    Gold Member

    So I'm not the only one who is waiting for this!

    I'm skeptical about the "habitable zone" idea, though.
     
  4. May 8, 2016 #3
    'Habitable zone' though doesn't mean the planet is actually habitable, only that liquid water might be possible at that distance from the star where the planet is orbiting.
    In the solar system Venus and Mars are technically within the habitable zone, but for different reasons neither one really does have liquid water.
    (Venus has too much atmosphere and Mars not enough)
     
    Last edited: May 8, 2016
  5. May 8, 2016 #4

    Vanadium 50

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2017 Award

    Another example is the moon. Not very habitable.
     
  6. May 10, 2016 #5

    mfb

    User Avatar
    2017 Award

    Staff: Mentor

    Not from the K2 mission...

    NASA's Kepler Mission Announces Largest Collection of Planets Ever Discovered

    Now we have ~3300 confirmed exoplanets, 2300 of those from Kepler.

    The update is mainly based on mathematics. They had all those candidates, but previously they analyzed every candidate by hand. The first big release of confirmed candidates came from transit timing variations a while ago, which allowed to confirm the existence of ~750 exoplanets. Now the statistical tools are more powerful - they can assign a probability to be a true planet to every candidate. Those 1284 planets got a probability of more than 99%. The huge number has a caveat, however: >99% still means a few of them won't be actual planets!

    9 of the planets could be rocky planets in the habitable zone, increasing the set of those planets to 21.
     
  7. May 10, 2016 #6
    Here is more on the above.
    https://iopscience.iop.org/article/10.3847/0004-637X/822/2/86/meta
     
  8. May 11, 2016 #7
  9. May 12, 2016 #8
    I'm skeptical too. Right now it seems like the "Habitable zone" is considered the most likely place to find life because liquid water should exist there. It's no guarantee as you said, Mars, Venus, and the Moon all exist within it and have no liquid water.

    There is exactly one planet in our solar system that has liquid water and is in the habitable zone. There are two moons much further out that absolutely have liquid water, and several more that might. The question is, does liquid water have to be on the surface for a planet to be habitable, or not? If all we're looking for is liquid water, that habitable zone is meaningless because tidal forces of giant planets can liquify water just as easily as the sun can and they seriously outnumber planets.

    I think we'll find that the majority of life in the universe will exist outside of the habitable zone. Of course, with a sample size of one, it's not possible to even make an educated guess one way or the other, but if discussing purely the existence of liquid water, the sample of the solar system favors moons around giant planets, not planets in the habitable zone.
     
  10. May 17, 2016 #9
    "Habitable Zone" is really a misnomer. To be more accurate it should be called a "Stellar Liquid Water Zone." It also makes certain assumptions, such as an atmospheric surface pressure greater than 611.657 pascals.

    There are problems with exoplanets that orbit red dwarf stars. The biggest problem is that a lot of these red dwarfs are "flare stars." Since the habitable zone of a red dwarf is so close to the surface of the star, these solar flares can play havoc with any atmosphere on an exoplanet within the habitable zone of the star. Another problem is the axial tilt of the exoplanet.

    The window for life on an exoplanet within the habitable zone of a red dwarf may be too short. So while red dwarf stars may consist of ≈76.45% of the main sequence stars in the Milky Way galaxy, they probably do not present a good candidate for life.

    See also:
    Tidal Venuses: Triggering a Climate Catastrophe via Tidal Heating - arXiv 1203.5104
     
  11. May 19, 2016 #10
    On the subject of Kepler/exoplanets, if all goes according to schedule :DD the addition of the next generation observatories (WFIRST-AFTA, LSST and EUCLID) should revolutionize not only the search for exoplanets but our understanding of cosmology in general. The capabilities of these missions combined have the potential to not only image exoplanets but bring us out of the "dark ages" regarding dark energy/matter, (pun intended). Rather than a lot of copy/paste or rewriting information that I can't improve on, I will include the following links for anyone inclined to read up on the missions.
    http://wfirst.gsfc.nasa.gov/index.html
    http://wfirst.gsfc.nasa.gov/science/WFIRST_FactSheet_final.pdf
    http://www.lsst.org/
    http://pcos.gsfc.nasa.gov/physpag/meetings/AAS_Jan2014/Euclid_AFTA_Sparke_PhysPAG_5Jan2014.pdf

    Hoping the gif animation works, it is supposed to show caparisons between Hubble and WFIRST's field of view.
     

    Attached Files:

  12. May 23, 2016 #11

    um, why?
     
  13. May 23, 2016 #12

    ProfuselyQuarky

    User Avatar
    Gold Member

    If you're asking why I'm skeptical, @newjerseyrunner pretty much said it in post #8 :smile:

    Anyway, I never quite understood why so many people put so much effort and invest so much money on looking for extraterrestrial life when we can barely manage taking care of our own planet :DD
     
    Last edited: May 23, 2016
  14. May 23, 2016 #13

    D H

    User Avatar
    Staff Emeritus
    Science Advisor

    I just cleaned up a bunch of off-topic posts, some of them on a banned topic. We do not discuss conspiracy theories or crackpot notions at this site.


    Discussions about Planet Nine are allowed at this site, but not in this thread. This thread is about a large list of exoplanets recently released by the Kepler project.
     
  15. May 24, 2016 #14
    I'm sorry for interrupting but...

    The study of Exoplanets shows how an extraordinary amount of potential exoplanets have been discovered in a number of programs, but what is the use of cataloging all of this information? Is it for us to better understand the formation of exoplanets, how they are created, etc. To simply go forth in the name of Discovery (Fine by me). Or maybe to discover out the encounter's these exoplanets faced in their development and how this applies to Humanity and it's own solar system/Planet?

    Again sorry to interrupt this thread with this post (It's fine by me if this question is relocated or even deleted) but it is somewhat distracting to think just what these discoveries serve a purpose for.
     
  16. May 24, 2016 #15
    Your post got me thinking, so I am researching your question... I thought I'd share this link taken from http://kepler.nasa.gov/ (seriously)
    http://www.theonion.com/article/new-solar-system-discovered-four-feet-from-earth-1094
    I'll search for realistic answers to your post but please be patient.
     
  17. May 25, 2016 #16

    D H

    User Avatar
    Staff Emeritus
    Science Advisor

    This was a good interrupt, thank you!

    Kepler cost us $550 million. That's a lot of money! Think of how many starving children that would have fed! What's the point?

    I did not mean that. What's the point of the Louvre, or on a much lesser scale, your neighborhood park? There has to be some place in our national and international budgets for discovery, for art, and for esthetic.

    Even with its myriad problems (sensors not performing as well as planned, two out of 42 sensors that failed, and two out of four reaction wheels that failed), the Kepler mission has shown us so much. It has shown us that there are indeed lots of other planets (pedantically correct: exoplanets) out there. Now that we know that, there's a next step that needs to be performed. Failing to do that next step means we are no longer curious apes.
     
  18. May 25, 2016 #17
    All of the above. Is not the purpose of science to gain a better understanding of the universe? The more we are able to observe the better our understanding becomes. Already our observations of exoplanets and other solar systems have given us new insights into our own solar system and its formation. Every time we discover anything new about the universe it serves a purpose and benefits us all.
     
  19. May 25, 2016 #18
    Thank you for helping me get over my confusion and for providing such a great source of information, I am relieved to finally have this nagging question solved! :smile:

    But to get back to the point of this thread, I wonder what Kepler's future discoveries might bring us and Humanity as a whole.
     
  20. May 25, 2016 #19
  21. May 25, 2016 #20

    mfb

    User Avatar
    2017 Award

    Staff: Mentor

    The most dramatic possible future discovery would certainly be life on exoplanets (and all the follow-up discoveries). But even if we don't find that, we can study how habitable other planets are, and how many planets like the Earth exist in our galaxy. It would tell us about the odds that life develops, and help to estimate some of the factors in the Drake equation. We can learn more how planetary systems form, which improves models of our own planetary system as well (where we can only look at the current state, not at the earlier evolution).
     
  22. May 25, 2016 #21
    A quick question on a Red Dwarf's hability... On red dwarfs there is a tidal heating system caused by the dwarf that often changes levels of tempature drastically, affecting the planets orbiting it
    For Reference: http://www.centauri-dreams.org/?p=34157

    If this was correct, how would it be possible for complex life forms to exist on these planets which such a dreadful environment that could spell doom for an entire species because of the changes of the red dwarf's output?

    My solution is somewhat simplistic and very general, my reasoning is that life often finds some way around these problems. With this reasoning in mind, would it not be possible for life on these planets to find some way to survive this grueling environment? (Maybe being able to detect high levels of temperature change and being able to react so that the affects are somewhat reduced?)


    Also... (I know I ask a lot of questions) What is the exact probability of planets with the ability to support life, or at least water, forming in a solar system? (Assuming that this solar system contains a stable G2V star)
     
  23. May 25, 2016 #22
    We can also hypothesize about the early evolution of our solar system by observing exoplanetary systems. None of the following studies existed before we first observed "hot Jupiters" around other stars.

    See:
    Accretion of Uranus and Neptune from inward-migrating planetary embryos blocked by Jupiter and Saturn - arXiv 1506.03029
    Jupiter's Decisive Role in the Inner Solar System's Early Evolution - arXiv 1503.06945
    Two phase, inward-then-outward migration of Jupiter and Saturn in the gaseous Solar Nebula - arXiv 1107.5656
    Outward Migration of Jupiter and Saturn in Evolved Gaseous Disks - arXiv 1207.2737
    A low mass for Mars from Jupiter's early gas-driven migration - arXiv 1201.5177
     
  24. May 25, 2016 #23
    Except that "life often finds some way around these problems" is not reasoning, that is wishful thinking. Reasoning would be an attempt to explain how life finds a way around the problems of tidal heating, tidal locking, and massive solar flares. While I certainly would not rule out the possibility of complex life around spectral type M main sequence stars, the window of opportunity for complex life to evolve seems rather short - bordering on non-existent. Therefore, spectral type K, G, and F main sequence stars seem like better candidates than red dwarfs, if the goal is to locate complex life forms.

    Thus far we have not discovered any exoplanet with liquid water on its surface, therefore, it is impossible to determine the probability of such an exoplanet existing. All we can say for certain is that we know of at least one - Earth.
     
    Last edited: May 25, 2016
  25. May 27, 2016 #24
    Why is the window for developing life shorter? M main sequence stars are known for having a much longer lifespan than G sequence stars, many of them are more than twice as old the the sun. And if the assumption that lifeforms developed a way to deal with the radiation and tidal locking is correct life would have much more time to evolve. It could be possible that life exists on such planets only beneath the earth or at the bottom of the oceans, avoiding the extreme radiation on the surface. The evolution of complex life is of course more unlikely. The only opportunity are M dwarfs who have ceased the flares and gained more stability within time, therefore providing a more stable environment for evolution. Another theory suggests that lifeforms around M dwarf planets are evolving much faster than on Earth (every night-day-cycle) because of the flares. Of course you can say it's pointless to assume and speculate, but what can we do beside making speculations? With our current technology there is no way to observe the planets we find with telescopes in detail. Isn't it better to think things through than to just collect data and be sad about not knowing more?
     
  26. May 27, 2016 #25
    True, speculation is just fine as long as we do not begin to accept this speculation as truth. It is VITAL that we, humanity, acknowledge the great unknowns in our knowledge, for knowing that there is something out there that is unknown has inspired us to grow for the last few centuries. However if we do go into some form of stalemate, such as how in the 16th century, most people refused to acknowledge the Heliocentric theory. Something today that we now think today as ovbious. So in conclusion it is fine for humans to speculate on just what lies out there in the great unknown, but it is important that we do not alter these speculations and change them into possibly false facts.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted