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This is interesting...

JackNJackN <font color=#99FF99>Lightwave Alien</font>
in Zocalo v2.0
Tripped over this looking at other Pics of the Day...

[URL=http://antwrp.gsfc.nasa.gov/apod/ap040316.html]Sedna[/URL]

I mean the article, not the image...

;)

Comments

  • BigglesBiggles <font color=#AAFFAA>The Man Without a Face</font>
    I saw that ages ago! March 16 to be exact. :)
  • MartianDustMartianDust Elite Ranger
    What I can't understand is why we didn't see this planet aeons ago when we can see so much further!
  • BigglesBiggles <font color=#AAFFAA>The Man Without a Face</font>
    Two things: firstly, there's a [b]lot[/b] of sky, and kupier belt objects are very, very small. Secondly, telescopes are designed to see a very long way. Looking at things like this is like trying to read a book that is 1cm from your eyes. You simply can't focus on something that close.
  • shadow boxershadow boxer The Finger Painter & Master Ranter
    Sedna also supposed to have a low albedo... (no not libido gutterminds 'AL-bedo')... which means its basically dark/black, non reflective, hard to see...
  • Random ChaosRandom Chaos Actually Carefully-selected Order in disguise
    You're the gutter mind that thought to mention libido :p
  • E.TE.T Quote-o-matic
    [QUOTE][i]Originally posted by Biggles [/i]
    [B]Secondly, telescopes are designed to see a very long way. Looking at things like this is like trying to read a book that is 1cm from your eyes. You simply can't focus on something that close. [/B][/QUOTE]
    I don't think that there's much difference in focusing between thousands kms and million kms.
    (try with camera: there's big difference between half meter and one meter, but after ten, twenty meters it pretty much same if target is at distance of 50 meters or 500 meters)

    The main reason is that they're dim objects, also they are far enough that their movement is very slow compared to asteroid belt's objects.
    Closer objects "move" much faster, for example 2002NY40 was so close to earth that you could see movement in few seconds.
  • ShadowDancerShadowDancer When I say, "Why aye, gadgie," in my heart I say, "Och aye, laddie." London, UK
    i think biggles is right. its to do with the scale of things. sticking with the metres example, the big telescopes are designed to look at things 20m away, but this planet is on the order of 1cm away. its very hard to focus on something that close
  • MartianDustMartianDust Elite Ranger
    Thanks guys! I always wondered with things like that. Makes sense. :)


    [QUOTE][i]Originally posted by Random Chaos [/i]
    [B]You're the gutter mind that thought to mention libido :p [/B][/QUOTE]

    Agreed! :)
  • ShadowDancerShadowDancer When I say, "Why aye, gadgie," in my heart I say, "Och aye, laddie." London, UK
    lol, we've just been doing this in my astronomy lectures so i suppose i should know something about it.......although that assumes that i actually go to the lectures:D
  • E.TE.T Quote-o-matic
    [QUOTE][i]Originally posted by ShadowDancer [/i]
    [B]i think biggles is right. its to do with the scale of things. sticking with the metres example, the big telescopes are designed to look at things 20m away, but this planet is on the order of 1cm away.[/B][/QUOTE]
    It's not about differences between distances.
    It's all about difference between angles in which light hits the mirror or lens.
    That's what determines need for refocus.

    For example when I use my reflector I don't have to refocus to see moon after I've looked galaxy thirty million light years away.

    Also for cameras it's same if distance is 50 meters or infinite. (because angle of incoming light doesn't really change anymore)
  • ShadowDancerShadowDancer When I say, "Why aye, gadgie," in my heart I say, "Och aye, laddie." London, UK
    like i said, i [I]should[/I] know something about it......:D
  • BigglesBiggles <font color=#AAFFAA>The Man Without a Face</font>
    [QUOTE][i]Originally posted by E.T [/i]
    [B]It's not about differences between distances.
    It's all about difference between angles in which light hits the mirror or lens.
    That's what determines need for refocus.

    For example when I use my reflector I don't have to refocus to see moon after I've looked galaxy thirty million light years away.

    Also for cameras it's same if distance is 50 meters or infinite. (because angle of incoming light doesn't really change anymore) [/B][/QUOTE]

    That makes sense.
  • bobobobo (A monkey)
    Current images from [URL=http://hubblesite.org/newscenter/newsdesk/archive/releases/2004/14/image/a]Hubble[/URL] seem to show there is no moon, as shown in the drawing.

    [quote]It is surprising that Hubble does not see a suspected moon near the planetoid. Either the moon's not there, or, far less likely, it is being eclipsed by Sedna, or it is transiting Sedna.[/quote]
  • MartianDustMartianDust Elite Ranger
    [QUOTE][i]Originally posted by E.T [/i]
    [B]For example when I use my reflector I don't have to refocus to see moon after I've looked galaxy thirty million light years away. [/B][/QUOTE]

    Just how big is your telescope?! Mustbe very powerful if you can look that far? :)
  • JackNJackN <font color=#99FF99>Lightwave Alien</font>
    [QUOTE][i]Originally posted by MartianDust [/i]
    [B]Just how big is your telescope?! Mustbe very powerful if you can look that far? :) [/B][/QUOTE]

    The SOB has a jump gate!

    I knew it!

    :mad:


    :p
  • E.TE.T Quote-o-matic
    [QUOTE][i]Originally posted by MartianDust [/i]
    [B]Just how big is your telescope?! Mustbe very powerful if you can look that far? :) [/B][/QUOTE]
    This one: (with "full manual" tracking)
    [url]http://www.telescopes.ru/product.html?cat=1&prod=7[/url]
    [url]http://www.cloudynights.com/reviews/Tal-1.htm[/url]

    And it's not about size of telescope, it all about brightness of object.
    With 40 cm telescope you could see optical afterglows of GRB's which happen other side of universe.

    [url]http://www.ursa.fi/sirius/nytt/nytt_info.html[/url]
    [url]http://adsabs.harvard.edu/cgi-bin/nph-bib_query?2002JAVSO..30..126O[/url]
  • bobobobo (A monkey)
    [QUOTE][i]Originally posted by E.T [/i]
    [B]And it's not about size of telescope, it all about brightness of object. [/B][/QUOTE]
    Don't delude yourself. Its always about size. ;)
  • MartianDustMartianDust Elite Ranger
    Interesting read ET, thanks. :)

    [QUOTE][i]Originally posted by bobo [/i]
    [B]Don't delude yourself. Its always about size. ;) [/B][/QUOTE]

    Hey we've already had this discussion about size! Size doesn't matter. ;)
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