The Galaxy is a Crowded Place – A Series

Discussion in 'Community Discussion' started by Irishman, Apr 24, 2014.

  1. Irishman macrumors 68030

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    The Galaxy is a Crowded Place – A Series

    One of the things that mankind’s search for exoplanets – planets located outside our own solar system – has shown us is that there are a lot more of them out there than we initially thought.

    As of this morning, we've found 1,774 exoplanets, a good chunk of them (962) found by the Kepler mission! They have a backlog of about 3,845 planet candidates for it to work through. Way back in 1989, we found the first exoplanet – HD114762 b (nicknamed Latham’s Planet, after its discoverer) – because of its great mass (10.98 Jupiter masses). That mass causes it to exert a small tug on its star due to its radial velocity, making the star “wobble”. HD114762 b is situated 128.7 light years from Earth, with a surface temperature of about 487K.

    So, I thought it would be fascinating to explore our galactic neighborhood, beginning with those closest to us, working our way further into the galaxy.

    Of course, as many of us know, that means we’ll start with Alpha Centauri B b:

    For long-time Star Trek fans, it probably won’t come as a surprise that we found a planet around the closest star to us. They probably will be surprised by how recently that discovery happened – two years ago in 2012! Alpha Centauri B b is interesting because it’s an Earth-mass planet (1.13 Earth masses) extremely close to its star (only .0400 AU) away. That means it whips around its star (1.227 solar masses), with a very short year (3.23 days)! It makes sense that we found this planet by the same radial velocity “wobble” indicator as referenced above. Alpha Centauri B b is 4.37 light years from Earth, and is, so far, the only planet in its system.

    Well, that’s it for this time! A huge part of my decision to keep the series going will be reader feedback. If it’s something you find useful, entertaining, or informative, please let me know here in the thread! If noone’s digging it but me, I’ll get that message quickly.
     
  2. Macman45 macrumors demi-god

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    #2
    Interesting stuff. I find it hard to comprehend the sheer size and quantity of what mankind has ALREADY found. A year of 3.62 days is strange, but the " wobble " in a planets orbit is said to indicate the possibility of life, based on what we know about our own solar system, and of course Earth.

    Who knows how long it will take to discover life elsewhere, but I am firmly of the opinion that it must exist...we are currently bound by our own laws of physics, meaning we are unable to reach any further than Mars, and that's a huge stretch.

    I'd like to see a mission to the Red Planet in my lifetime, but I'm not holding my breathe....it's such a tough job with the existing technology.
     
  3. Huntn macrumors G5

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    #3
  4. LIVEFRMNYC macrumors 603

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    A year of 3.62 days would make for some rapidly changing weather and seasons.
     
  5. Huntn macrumors G5

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    If there was tilt absolutely. Makes me wonder about the day/night cycle and nausea. :eek:
     
  6. mrkramer macrumors 603

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    My guess is with how close it is to its sun you would burn up before having to worry about either of those.
     
  7. Scepticalscribe Contributor

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    #7
    Thanks a lot for starting a thread on such a wonderfully interesting topic and for your OP. And, please, do, continue to post and add further data and material.

    Yes, I do find this sort of information both entertaining and informative; above all, I find it extremely thought-provoking, and awesomely absorbing. As a kid, I loved Star Trek (the original); as an adult, STNG was one of my few must-sees on TV.

    Indeed, I used to watch the moon landings, entranced, and read - nay devoured - books and articles on this topic. I'll still read about, or watch programmes about such stuff.
     
  8. Zombie Acorn macrumors 65816

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    #8
    Must have been a similar sentiment before we went to the moon
     
  9. carjakester macrumors 68020

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    #9
    or like living in chicago! :D
     
  10. localoid macrumors 68020

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    #10
    The surface temperature of Alpha Centauri Bb is estimated to be about 1,200 °C.

    Kepler-186f, on the other hand, is the most earth-like, potentially habitable, exoplanet that's been found to date, although it is much further away from the earth, @ 500 light-years from earth.

    Exoplanets have been found in a habitable zone before, however Kephler-186f is first Earth-sized planet that's been found (the others were 40 percent larger than Earth).

     
  11. Scepticalscribe Contributor

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    #11
    Great clip and terrific story - thanks for posting it, and I hadn't seen that particular news report.

    I must say that I love this term 'The Goldilocks Zone' which is used in this context - it is brilliant; beautifully descriptive, immediately comprehensible and utterly unforgettable.
     
  12. localoid, Apr 27, 2014
    Last edited: Apr 27, 2014

    localoid macrumors 68020

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    #12
    The Space Sunflower...

    Soon, we may get an even better look at Earth-like rocky planets orbiting around nearby stars, by using a spaceship that uses a giant starshade, that's being developed by NASA's Jet Propulsion Laboratory in Pasadena, Calif.



    Thanks. "Goldilocks Zone" certainly rolls off the tongue easier than the "Circumstellar Habitable Zone" (CHZ), doesn't it? ;)
     
  13. SandboxGeneral Moderator

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    #13
    Oh I love this stuff! I did a little reading about Kepler 22b a couple of years ago and, at the time, I believe, it was the most Earth-like exoplanet known.

    It's in what is called the habitable zone around it's sun and the average surface temperature is 72℉ or 22℃. It's located about 600 light years away from Earth and was discovered in 2009.

    I even wrote a little article on my website with references to it. Though there are some holes in my research and missing ideas I still want to add, I still thought it was a good write.

    http://www.space.com/24128-kepler-22b.html

     
  14. Huntn macrumors G5

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    #14
    It makes me wonder what are the odds that the development of planets in the "life sweet spot" would lead to a predominantly O2 atmosphere? It's fiction, but I am reminded of Pandora. :)
     
  15. SandboxGeneral Moderator

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    #15
    I like to believe, that given the vastness of not only our galaxy, but the universe as a whole, or even the multi-verse, that there has to be other habitable planets that could sustain life as we know it to be.

    It's just a matter of finding it, not that we'd likely ever be able to actually visit it even if we could travel at light speed.
     
  16. localoid macrumors 68020

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    #16
    The Fermi paradox is the apparent contradiction between high estimates of the probability of the existence of extraterrestrial civilizations and the lack of evidence for, or contact with, such civilizations.

    One of the hypothetical explanations for the paradox is that "it is the nature of intelligent life to destroy itself".

    In the following video, Michio Kaku ponders the question of whether humankind will destroy itself before we're able to achieve inter-stellar/galactic explorer status.

     
  17. Huntn macrumors G5

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    Great video! I can easily see Type 0 civilizations blowing themselves up. I vote for Star Trek Next Generation, a society built on a "we is greater than me" standard, a socialist utopia. If we want to advance to a type 1 civilization, this is the only path I see. I don't want to turn this into a PRSI discussion, so I'll stop there. :)
     
  18. Scepticalscribe Contributor

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    #18
    Yes, agree with you completely. Actually, I find myself rather partial to the 'world view' (and 'universe building' concepts) of STNG; a positive, inclusive, thoughtful perspective on the universe
     
  19. Irishman thread starter macrumors 68030

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    #19
    The Galaxy is a Crowded Place – A Series (Part 2)

    The Galaxy is a Crowded Place – A Series (Part 2)

    Welcome back. As of today, we’re up to 1,776 exoplanets, and next on our list for the series is epsilon Eridani b:

    Epsilon Eridani b orbits its gas giant star about 10.44 light years from Earth, at a distance of 3.39 AUs from that host star, and has a 2,502-day year. Its surface temperature is 111.8 K. As of right now, it’s the only known planet in its system, and was discovered quite recently in 2000. It was found using the same radial velocity technique as was Alpha Centauri B b, as it was measured exerting a gravitational tug on Epsilon Eridani, a K2 V-type star.

    As far as supporting life, due to its distance from its type of star (3.39 AU), it is well beyond the “Goldilocks Zone” there – which is between .65 – 1.21 AU from the star. Sadly, this means no life as we know it can exist on Epsilon Eridani b.

    Thanks so much for the feedback thus far! It’s clear that you guys are enjoying it as much as I am, so I’ll soldier on with the series.
     
  20. chown33 macrumors 604

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    I think I prefer CHZ. Yeah, it has to be explained a few times, but after that, you get to say things like, "Such-and-such exoplanet looks like a good candidate because it's in the cheese."
     
  21. localoid macrumors 68020

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    #21
    Thought I'd post this video, which takes a look at how astronomers find exoplanets, and what it means to call them Earth-like. It also traces the history of planetary science back three thousand years and examine Earth's changing status in the cosmos -- earth was once the center of the universe, now it's just another rock in the sky.

     
  22. Irishman thread starter macrumors 68030

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    #22
    The Galaxy is a Crowded Place – A Series (Part 3)

    This time we’ll be taking a slight detour on our trip through the galaxy, on our search for exoplanets, in what is proving to be a very crowded galaxy. Just a week ago, I would have been making a different kind of post in my series to highlight the exoplanets that are the closest to our star. But due to the rapid advance of science, a new discovery was announced just a few days ago that has changed that.

    What is it?

    The answer is Kapteyn b. Kapteyn’s star is named – as is tradition – after its discover, the Dutch astronomer Jacobus Kapteyn. There are several qualities about Kapteyn b that make it special: 1) Its proximity to Earth, which is 12.75 light years, and 2) Its age, which is roughly 11 billion years old. To put it into perspective, the Earth is about 5 billion years old. Life on Kapteyn b has had over twice as long to evolve, 3) Its mass is 4.8 Earth masses, which puts it into the category of super-earths, 4) Its orbit around its M1.0 type star is 48.62 days, which puts it within its Goldilocks zone of .07-.15 AUs. This delicate combination of qualities make Kapteyn a place which should keep our attention for a long time to come.

    Kapteyn b isn’t alone in its system. We have - so far - found a second planet, called Kapteyn c, another super earth that is 7.0 Earth masses, orbits further away – 121 days - from its host star, and thus, too far outside of its habitable zone to support life as we know it.

    Both Kapteyn b and Kapteyn c were found in 2014 using the tried and true radial velocity method.

    Here is a good starter link to more of the methodology of how we learned what we know about these planets. http://phl.upr.edu/press-releases/kapteyn
     
  23. SandboxGeneral Moderator

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    #23
    I just read an interesting article on io9.com about this binary star system.

    We've Discovered a Binary Star System Whose Planet Is in Stable Orbit

     

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