Even Earth’s mightiest telescopes aren’t up to the task of imaging Apollo lunar landing sites. A lack of resolution is the biggest reason why

Even Earth’s mightiest telescopes aren’t up to the task of imaging Apollo lunar landing sites. A lack of resolution is the biggest reason why

Magnification is just how much you can zoom in on an object, making it look bigger. That’s important because while astronomical objects are physically big, they’re very far away, so they appear small in the sky. Magnifying them makes them easier to see.

Resolution, on the other hand, is the ability to distinguish two objects that are very close together. For example, you might perceive two stars orbiting each other—a binary star—as a single star because they’re too closely spaced for your eye to separate. You can’t resolve them. Looking through a telescope with higher resolution, however, you might be able to discern the separation between them, revealing that they are two individual stars.

But isn’t that just magnification, then? No—because magnification only makes things bigger!

  • ChonkyOwlbear@lemmy.world
    181·
    2 months ago

    Can you take a microscope and hold it up to look at things far away? No. Can you use binoculars to look at skin cells? No.

    The shape of the lenses and their positioning in respect to each other vary depending on whether the magnifier was designed to focus on small close objects or large far objects.

    The Hubble was made to look at large objects an immensely far distance away. Looking at an astronaut on the moon is a comparatively small and close target. It simply isn’t built to do that.

    • herrvogel@lemmy.world
      31·
      2 months ago

      That’s not what the article is saying though. The article is talking about angular resolution. Hubble could focus on the surface of the moon all it wants, it still won’t have the angular resolution to resolve things as small as a human at that distance. Its lenses are far too small to distinguish things smaller than about 100 meters when looking at the moon IIRC…

    • cynar@lemmy.worldEnglish
      1·
      2 months ago

      This issue is that it’s actually too far, for its magnification.

      The comparison I heard is that to see the lander base, the magnification would be such that, from earth orbit you could pick out an individual human hair on the ground.

      Moving closer gets you a huge boost in resolution.