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

Jupiter's Moons

  1. Jan 18, 2015 #1
    Hi all. I'm new here but excited to be mingling with so many intelligent people.

    I'm British but live in Romania (Near Brasov) and 2 nights ago I was delighted to see some of Jupiters moons with the naked eye.

    I tried to get some pictures but without the right equipment it was a bit of a disaster. Here is the best one I got, Before I snapped the picture, what I could see on the screen was Jupiter and 3 moons.

    I was taking the picture though double glazed windows in my bedroom so you can see the the refraction above and left of Jupiter. Interestingly though, in that refraction you can see the current phase of the planet as I was able to see with good binoculars...
     

    Attached Files:

  2. jcsd
  3. Jan 18, 2015 #2
    I was under the impression Jupiter did not exhibit phases as seen from earth. Jupiter has always been fully illuminated whenever I have viewed it.
     
  4. Jan 18, 2015 #3
    Maybe I'm imagining it then. I'm only using 8x40 binoculars and a camera with 200mm lens.. But that refraction in the window as well as what I was seeing though both optics looked a lot like a phase...
     
  5. Jan 18, 2015 #4
    It was probably distortion caused by the window -I guess. You will get much better results outside.

    I think binos are great to start with. Take them somewhere dark and you can see many objects. And with your digital camera and a tripod you can try some longer exposure pictures that will show you even more.

    Check these out. And welcome to PF!
    www.heavens-above.com
    http://www.astronomie.be/registax/
     
  6. Jan 18, 2015 #5
    I dont have a tripod yet but I set the camera up on the windowsill so It wouldnt move. When I tried long exposures (about 20 seconds) I ended up with long lines created by the planet because we are spinning too fast.. What is the optimum exposure time to get the most light but before the planet moves?
     
  7. Jan 18, 2015 #6
    That is a tough one. The motion is constant, I'm sure you know. So the longer the exposure the blurrier (is that a word?) the image. Unless you accomodate!
    There was a member on here, yesterday -I think, building a "barn door tracker" to allow longer exposures.
     
  8. Jan 18, 2015 #7

    russ_watters

    User Avatar

    Staff: Mentor

    Jupiter is bright, so you want short exposures, not long ones -- the picture in the OP is washed-out (too long).
     
  9. Jan 18, 2015 #8

    davenn

    User Avatar
    Science Advisor
    Gold Member

    just to clarify objects in the OP's image ......

    DSC02609a.JPG


    I seriously doubt you will see any of Jupiter's moons naked eye, tho they fall within the naked eye magnitude range .... M4.5 - 5.6, their close proximity to Jupiter means they are washed out with Jupiter's brightness
    Binoculars, large telephoto lens on a camera or small scope at a minimum are needed to separate them from the bright disk of Jupiter

    and with any those, the moons will be very close in to Jupiter and could be difficult to see being so close
    Good Bino's or a larger scope will easily split the 4 Galilean moons from Jupiter so you can see them separately

    here's an example from a 10 inch reflector telescope .....

    Jupiter-moons.jpg

    cheers
    Dave
     
    Last edited: Jan 18, 2015
  10. Mar 5, 2015 #9
    What you indicated is exactly what I was referring to. I looked up at Jupiter when i was going to bed and saw it was not round and that there was a little bit of extra light jutting out from the bottom left of it. Then with Binoculars (and then with confirmation with a star app on my phone) I saw that it was in fact 3 or 4 of the moons all lined up in that exact spot.
     
  11. Mar 5, 2015 #10

    russ_watters

    User Avatar

    Staff: Mentor

    Now, that would be a cool sight! I've never seen a moon of Jupiter naked-eye (and never thought about that method), but if two or more get close together, that would definitely be a plausible way to spot them. I need to try that myself!

    Slightly curiosity, slightly relevant -- are you overseas in the military, as your avatar picture would imply (not sure if you can tell me...)? Just wondering if you are in a place with exceptionally dark skies, especially compared to my bright suburban philly skies.
     
  12. Mar 5, 2015 #11
    I am british but I live in Romania near the town of Brasov. I'm right on the south east side of it with nothing but mountains between me and Jupiter that night.

    Regarding the military, I work for a private military company, spend way too much time in messed up places in the middle east and Africa.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook