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

Stereoscopic deep space imaging

  1. Dec 12, 2013 #1
    Hello people, first i need to say that i am quite a newb for astronomy.
    I have a idea about creating deep space stereoscopic images.
    I was wondered if it is usable to place two satellites(space telescopes) in heliocentric orbit, with distance approximately that of pluto , that are 180 degrees one from another - each on a different side of the sun. They would simultaneously take pictures of same sectors of space, thus creating a stereoscopic image of a star cluster, planetary system or whatever.
    I have calculated that this could create valuable stereo-images , by analogy of my stereoscopic view.
    I can clearly distinguish image dept at 10 km distance with my eyes, so i divided that distance with the distance between my eyes - 10km/6cm = 166666.666
    166666.666*(29.657*2) AU(pluto perihelion) =9.88566663e+06
    9.88566663e+06 /63241 AU(light year)= 156.31 light years.

    29.657*2 - pluto perihelion *2 - distance between the satellites
    all astronomical distances are in AU

    I think that dept perception can be distinguished even at distances greater then 10 km for human eye, and computer vision is clearly superior and more sensitive then the human eye.
    Still even if it is just 156 ly, there are thousands of stars to observe.
    Are my calculations valid?
    And could this idea be somehow useful for astronomy?
  2. jcsd
  3. Dec 12, 2013 #2


    User Avatar
    Science Advisor
    Gold Member

    Hi Bob, welcome to PF!

    What you're talking about is called parallax, and is routinelly used to determine distances to nearby stars. Rather than facing the technological challenges involved in placing telescopes in deep space, astronomers tend to use the convenient natural solar satellite - the Earth. By making observations of a given objects at two times, half a year apart, they can observe the parallactic displacement of the target with respect to the so called "background stars". Earth's orbit only gives you 2AU triangulation base, but you should see how the loss of accuracy over your ~60 AU proposition is outweighed by the convenience factor.

    Wiki has got a nice article on the subject:
  4. Dec 12, 2013 #3

    Jonathan Scott

    User Avatar
    Gold Member

    It is possible to get more accurate observations from space, but there's no need to send a satellite very far as the Earth itself moves to either side during the year.

    The Hipparcos satellite made parallax and proper motion observations of this type from Earth orbit. (It was intended to go into geostationary orbit, but ended up in a transfer orbit instead, but was still able to achieve its mission objectives).
  5. Dec 12, 2013 #4


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Of course there is only a handful of stars close enough to have measurable parallax. For the vast majority of stars this would not help much if at all.
  6. Dec 13, 2013 #5
    Yeah... Parallax , i have forgotten that term
    well Wikipedia sort of answered my questions.
    Given a second thought , it is not so bright idea to send two satellites on a 12 year trip to function for a perhaps half of that time, given that hubble space telescope was regularly repaired.
    And 2 AU or 60 AU is not as essential as i previously thought.
    Thanks for the help ppl :)
  7. Dec 14, 2013 #6

    D H

    User Avatar
    Staff Emeritus
    Science Advisor

  8. Dec 14, 2013 #7


    User Avatar
    Science Advisor

    The Hipparcos satellite measured the parallax of over 50,000 stars. I guess this is a "handful" if you have big hands! The Gaia satellite, set to launch soon, will extend this to a billion stars. Parallax measurements just keep getting better. Gaia has a goal of positional accuracy of 24 μas, which is the parallax of an object at about 100,000 light-years distance. This is most of the stars in our galaxy.
  9. Jan 2, 2014 #8
    You underestimate today's optics, CCD's, and the clarity afforded by being in space. Read up about Gaia mission. ~15 µas precision for stars with magnitude 15 and less!!!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook