Why don't we have as many Hubble pictures of Luna as we do of faraway objects?

Discussion in 'Astronomy, Exobiology, & Cosmology' started by StrangerInAStrangeLand, Nov 16, 2008.

  1. StrangerInAStrangeLand SubQuantum Mechanic Valued Senior Member

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    Seems quite silly to me. Like exploring Luna before other continents.
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  3. AlphaNumeric Fully ionized Registered Senior Member

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    Because it's not designed to look at such close objects and the brightness levels would probably 'blind' the optics.
     
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  5. StrangerInAStrangeLand SubQuantum Mechanic Valued Senior Member

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    I didn't think I needed to point out it wasn't designed that way.
    Whatever the problems might be, it doesn't make sense to put Hubble up there & not even try to see what we can of Luna.
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  7. Janus58 Valued Senior Member

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    It makes plenty of sense, since it wouldn't be worth doing. Even as close as the Moon is, the Hubble wouldn't be able to resolve anything smaller than 185m on its surface. We got better resolutions than that of the Moon's surface in the 1960's with the Lunar Orbiter series of probes, with the added advantage of being able to image the far side also.

    It makes much more sense to send a probe to the Moon to take close up images than it would to try and design the Hubble so that it would have been able to take pictures of the Moon.
     
  8. StrangerInAStrangeLand SubQuantum Mechanic Valued Senior Member

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    Resolutions of no less than 185m are no good but resolutions of hundreds of light years are. Nonsense.

    Are we doing that?
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  9. Janus58 Valued Senior Member

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    As I already pointed out, we already have images taken in the 1960's that are better than those that could be taken by the Hubble. And yes, we have sent other probes to map the Moon; Clementine is an example.

    Future missions include the Lunar Reconnaissance Orbiter, scheduled to launch in April of 2009. Its camera should be able to resolve some of the larger pieces of equipment left behind by the Apollo missions.
     
  10. BenTheMan Dr. of Physics, Prof. of Love Valued Senior Member

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    Considering galaxies are millions of light years across...yeah.
     
  11. StrangerInAStrangeLand SubQuantum Mechanic Valued Senior Member

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    Yes, I saw you point that out the 1st time.

    That's good. It still doesn't make sense not to have enabled Hubble to do whatever could be done to photograph Luna while it's there & the probes are not.
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  12. Janus58 Valued Senior Member

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    What good would it have do for the Hubble to take pictures of the Moon that are not as good as the photos that we have already taken of the Moon?
     
  13. D H Some other guy Valued Senior Member

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    Not nonsense. The moon is about 384,400 kilometers from the center of the Earth, or about 377,400 kilometers from the Hubble. The Hubble's the highest resolution camera, appropriately named the High Resolution Camera (HRC), has a pixel size of 28×25 milliarcseconds. At 377,400 kilometers, that 28×25 milliarcseconds pixel corresponds to an area of 51.23×45.74 meters. However, a 51x46 meter object on the Moon would be invisible to this camera. The Nyquist sampling theorem says that the smallest object that can possibly be resolved by any camera is twice the pixel size (linear, not square). This means the camera might be able to see a 102x91 meter object as a tiny dot. The camera isn't perfect and a one pixel object has zero meaning. You have to double the size again, 205x183 meters, to get the realistic resolution capability if the HRC were to view the Moon -- which it doesn't do because this camera is designed to look at very faint objects.
    The LRO is scheduled for launch next April. For more, see http://lunar.gsfc.nasa.gov.
     
  14. Nasor Valued Senior Member

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    Another major issue that I don't think anyone has pointed out yet is that when the hubble takes those pretty pictures of far-away stuff, it can spend DAYS gathering data for each image. You can do that when you're looking at stuff that's very far away because the apparent relative motion from parallax etc. is tiny. If you tried to take such an image of something that was close, you would probably end up with everything hopelessly blurred from all the motion.
     
  15. Ophiolite Valued Senior Member

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    I take it you have adapted your mountain bike so it can carry you across the Atlantic in about the same time and comfort as an Airbus. You haven't! Why ever not. I mean it's just silly to go to all the trouble of acquiring a transport device that is only any use for a very limited form of transport. What's the matter with you? Do you have comprehension difficulties? Lack of ambition? Wow!:shrug:
     
  16. leopold Valued Senior Member

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    it makes perfect sense.
    why waste the hubbles exceptional seeing power on an object we can see plainly and clearly by earth based telescopes?

    what do the 4 ones mean?
     

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