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General Astronomy, Cosmology and Space Exploration Discussion

Discussion in 'Science' started by BlueRaven, Jul 23, 2013.

  1. BlueRaven

    BlueRaven Member

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    I thought I'd update the thread title to make this a place for discussion of all topics relating to astronomy, astrophysics, cosmology, spaceflight and space vehicles, interplanetary biology... etc. etc.

    So ask away and OCAU's sciencey Dr. Karl type bods will try and answer. (No guarantees given as to accuracy of answers... check your own facts before opening your mouth down at the pub!).

    Some useful and interesting links follow (will be added to over time). The OP is at the bottom.
    Post or PM me if you have any favourite sites you'd like to see added. I'd love to see this list continually evolve. Thanks.

    International Space Administrations:
    Wikipedia List of Space Agencies - http://en.wikipedia.org/wiki/List_of_space_agencies
    US - NASA - www.nasa.gov
    - NASA TV - http://www.nasa.gov/multimedia/nasatv/index.html#.UiVRNz95fEs
    Europe - ESA - http://www.esa.int/ESA (see Wiki link for individual Nation's agencies)
    Russia - ROSCOSMOS - http://www.roscosmos.ru/#main.php?lang=en (in Cyrilic... English language link doesn't appear to work )
    Asia - APSCO - http://www.apsco.int (see Wiki link for individual Nation's agencies)
    India - ISRO - http://www.isro.org

    Educational/Research Institutions:
    JPL - http://www.jpl.nasa.gov/
    Caltech - http://www.caltech.edu/
    Ames Research Center - http://www.nasa.gov/centers/ames/home/index.html#.UiVQwT95fEs
    MIT - http://web.mit.edu/newsoffice/topic/space.html
    MIT Kavli Institute for Astrophysics and Space Research - http://space.mit.edu/
    CSIRO - http://searchext.csiro.au/search/search.cgi?query=space&area=site&collection=CSIROau_All&form=csiro

    Museums and Professional Societies:
    Smithsonian National Air and Space Museum - http://airandspace.si.edu/
    American Institute of Aeronautics and Astronautics - http://www.aiaa.org/#&panel1-5
    Royal Aerospace Society - http://aerosociety.com/

    Private Companies invested in Aerospace fields:

    SpaceX - http://www.spacex.com/
    Virgin Galactic - http://www.virgingalactic.com/
    Boeing Defense, Space & Security - http://www.boeing.com/boeing/bds/
    Lockheed Martin - http://www.lockheedmartin.com.au/us/what-we-do/space.html

    Space News Sites/Blogs:

    Space.com - http://www.space.com/news/
    Extreme Tech- http://www.extremetech.com/tag/space-travel
    Space Daily - http://www.spacedaily.com/
    Universe Today - http://www.universetoday.com/
    abc.net.au Space & Astronomy News - http://www.abc.net.au/science/news/space/
    Discovery Channel Space Portal - http://news.discovery.com/space

    Cool Spacey Stuff:
    Hubble Links
    Spitzer Links
    I.S.S. Links
    The Parkes Radio Telescope
    The Square Kilometer Array
    SETI@HOME
    EINSTEIN@HOME


    OP STARTS HERE:
    50 Years Of Space Exploration - An Orbital Map - www.extremetech.com/wp-content/uploads/2011/11/50_Years_Space_Exploration1.jpg
    Very cool graphic, thought I'd share.

    I remember being so excited when Cassini/Huygens launched in 1997. I was 18.
    And then excited all over again when the first pictures came back... the first probe launched in my lifetime that I was aware enough to witness, both the launch and the resulting data.

    Life got in the way for a while, and my interest in this stuff was overrun by the humdrum stuff of daily existence.
    But every now and again I come across something like this that makes me sit in wonder for a little while, and I feel like a kid again.
    I love StumbleUpon. :)
     
    Last edited: Sep 12, 2013
  2. /invariance\

    /invariance\ Member

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    As I don't follow space exploration, I found it quite surprising the no. of missions, especially to the moon, mars and venus.
     
  3. ikonz0r

    ikonz0r Member

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    I'm surprised how few have been to Mercury considering how close it is to us. I guess there may be technical issues as well as we have pretty well concluded there won't be any green men on the hell hole :cool:
     
  4. El Nermo Diablo

    El Nermo Diablo Member

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    Well, true, and outside that holds little interest for exploration outside its essentially geologically inactive with no atmosphere and lava one side and an ice cube on the other. And that fact its so small, moving so fast (in orbit) and too close to the sun. ;)
     
  5. synaptik

    synaptik Member

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    Awesome graphic. This was the "centerfold" of a National Geographic special space exploration edition a couple of years ago. I picked one up by chance when it came out, lots of great prints of images from Cassini, the Mars rovers and the moon landings.
     
  6. Parker Pete

    Parker Pete Member

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    How hot is it on Mercury?
     
  7. OP
    OP
    BlueRaven

    BlueRaven Member

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    Approx. +400°C in the sun, -200°C in the shade.

    No atmosphere to insulate it.
    Actually, there is a very thin atmosphere, but it does nothing to filter out the massive amount of Infrared/UV/Gamma ray energy that Mercury gets bombarded with from a very small distance (in cosmological terms) and conversely, it does nothing to stop the hemisphere that faces away from the sun dissipating all of its energy into space.
    Theory suggests that there would have been a more substantial atmosphere soon after the planet formed, but it was rapidly stripped away and sent streaming off into space by the solar wind.

    As ikonz0r pointed out above, this is the most likely reason there have been so few missions to Mercury.
    Designing a probe/rover that could withstand such extremes of temperature for longer than a few hours would be extremely difficult. :wired:
    They can do it with orbiting spacecraft, but a largely mechanical device like a rover would be a different story.
     
    Last edited: Aug 31, 2013
  8. Foliage

    Foliage Member

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    I would be incredible to just see what happens if you land a bunch of equipment on the cold side and then watch it turn to dust in minutes once the sun hits it!
     
  9. OP
    OP
    BlueRaven

    BlueRaven Member

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    One of the Soviet's early Venera probes to Venus had its camera lens cap melted on to the lens barrel within seconds of entering the incredibly hot atmosphere, they were scratching their heads for hours running diagnostics and trying to figure out why there was no data coming back... :lol:

    (Source: 1997 BBC doco "The Planets"... I still have my double-VHS copy floating around, can't bear to throw it out even though I haven't owned a VHS machine for about a decade :lol:)
     
    Last edited: Aug 31, 2013
  10. Veefy

    Veefy Member

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    Kim Stanley Robinson wrote a book called 2312 that is partially set on a moving city that follows the ever moving terminator between night and day on mercury bycrawling on an elevated track.

    Though really the scientific value of sending rovers there seems very limited.
     
  11. OP
    OP
    BlueRaven

    BlueRaven Member

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    A great setting for sci-fi (I'll have to read it, loved the 'Mars' series), but the mind boggles at how impractical a solution it is.
    Though I still think we should build it one day, with the answer to the question "why?" being... "because we can". :D

    You never know... we may one day send a rover to Mercury and discover a new form of life. Maybe some kind of bacterium or lichen that can protect itself from and/or make use of the intense radiation via some previously unknown biological mechanism, and then go into a kind of suspended animation when night falls.

    We have already discovered creatures here on earth than can survive for a substantial amount of time in the vacuum and radiation of space, and life here seems to have a funny way of popping up where we previously assumed it never could... at immense pressures in pitch black, highly acidic water near volcanic vents on the ocean floor, or inside solid Antarctic rock that hasn't seen liquid water or temperatures warmer than -40°C for millenia.

    The universe is a very big, very weird place. Nothing should be assumed, no possibilities ignored. :)

    EDIT: Although bang-for-buck in space exploration budgets is also something that can't be ignored, obviously. ;)
     
    Last edited: Sep 1, 2013
  12. Veefy

    Veefy Member

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    Of course I'm only saying its limited value based on current evidence, though its really more a case of "there are a bunch of far more interesting places we should be looking for life first given limited budget for robot/rover type missions". I mean some of the Jovian and Saturnian moons are a lot more interesting.
     
  13. OP
    OP
    BlueRaven

    BlueRaven Member

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    Absolutely true. And with our current knowledge of the extremes where life can survive, plus the wide range of atmospheric conditions, the high probability of liquid water, and high levels of geological activity on at least a couple of them, the giant's moons would seem the most likely place in the entire solar system for life to be found.

    And of course, there's plenty of excellent scientific reasons to explore them aside from a search for other forms of life.
     
    Last edited: Sep 1, 2013
  14. Danske

    Danske Member

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    Last edited: Sep 2, 2013
  15. Sphinx2000

    Sphinx2000 Member

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    Stumbled across this cool 2D info video the other day, thought it might be good here:

     
    ssar likes this.
  16. kripz

    kripz Member

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    If a meteor wiped out the dinosaurs millions of years ago and assuming some earth flew into space with life inside it and landed on another planet. Would you essentially skip parts of evolution? The worms and whatever life would die if it landed on the oceans of Titan but would the tiny things like bacteria and microbes survive? Single cell stuff?

    PS I don't know anything about biology.
     
  17. de_overfiend

    de_overfiend Member

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    @ kripz

    it has been proven that SOME species of bacteria will survive the heat and impact of entering a planets atmosphere. It has not been proven how long those bacteria will survive in space.

    As for skipping evolution, there might be a small step that might have been skipped by seeding a planet with bacteria, but it still has to evolve into a more complex life form yet.

    have a read of this: http://en.wikipedia.org/wiki/Panspermia
     
  18. OP
    OP
    BlueRaven

    BlueRaven Member

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    Thread title updated to encourage more interesting discussion along ^^these lines^^ and anything else you feel like really. :)

    Thanks man :thumbup:

    Thanks for sharing :thumbup:
     
  19. twisar

    twisar Member

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    Its an unknown, the only thing that would really survive would be the smallest organisms (and hardiest) like bacteria. Given that Bacteria (or their ancestors) appeared within a billion years of Earths creation, then if some landed on a barren Titan they'd have a billion years head start at so. I suspect they may find the conditions there too difficult to succeed as the conditions on Titany aren't what they're made for and they may never prosper or become more complex. They'd have to find a viable ecosystem quick or they'd go dormant and then eventually wither away. Possible, but unlikely.
     
  20. OP
    OP
    BlueRaven

    BlueRaven Member

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    It's possible that bacteria or other single-celled organisms, forcibly removed from their native environment and inserted into an extraterrestrial one, might actually be forced through an extended evolutionary process rather than a shortened one. Because whatever mutations or other evolutionary processes that have led the species to that point may not be beneficial in the new environment.

    At that stage, assuming any organisms can survive at all, evolution goes back to the drawing board and starts again with the first generation native to the new environment.
     

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