<p>If I interpret your system concept, you want to view over the horizon (OTH) by adding a distant mirror to your overall telescope optical prescription.<br>
First: it's not necessary to go into orbit, depending on how far OTH you want to view.<br>
Second, whether you try to place such a mirror on, e.g., a blimp or in orbit, the difficulties involved in launching, aiming, stabilizing, etc. a mirror of sufficient size to allow enough light-gathering at your ground location are greater than the difficulty in launching a spy satellite (of which there are many, each with a telescope comparable to Hubble's main scope).   </p>

<p>Third,  for optical reasons (try googling "shower-curtain effect adaptive optics")  viewing the ground from orbit suffers far less from atmospheric distortion effects than vice versa.  Far better to put the telescope in orbit and send digitized image data to the ground. </p>

CC BY-SA 4.0
2018-09-07T18:16:23.403Z
2018-09-07T18:16:23.403Z
Carl Witthoft
<p>Could a small curved mirror and/or lens in Earth's orbit be aimed at a different hemisphere from where you are be be viewed with a powerful telescope to see the ground through the mirror? Would a more powerful telescope than the Hubble see more or less because of the atmosphere diffracting light twice?</p>

<p>Bonus: Would sending a mirror to space cost less this way then a huge camera/telescope?</p>

<telescope><light><hubble-telescope><atmospheric-effects>
Looking at ourselves with a powerful telescope?
Muze
# Looking at ourselves with a powerful telescope?

(Asked by: username_0 on 2018-09-06)

Could a small curved mirror and/or lens in Earth's orbit be aimed at a different hemisphere from where you are be be viewed with a powerful telescope to see the ground through the mirror? Would a more powerful telescope than the Hubble see more or less because of the atmosphere diffracting light twice?

Bonus: Would sending a mirror to space cost less this way then a huge camera/telescope?

**Tags:** telescope, light, hubble-telescope, atmospheric-effects

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## 1 answers

### Answer by username_1 on 2018-09-07. Score: 3 | Accepted answer

If I interpret your system concept, you want to view over the horizon (OTH) by adding a distant mirror to your overall telescope optical prescription.  
First: it's not necessary to go into orbit, depending on how far OTH you want to view.  
Second, whether you try to place such a mirror on, e.g., a blimp or in orbit, the difficulties involved in launching, aiming, stabilizing, etc. a mirror of sufficient size to allow enough light-gathering at your ground location are greater than the difficulty in launching a spy satellite (of which there are many, each with a telescope comparable to Hubble's main scope).

Third, for optical reasons (try googling "shower-curtain effect adaptive optics") viewing the ground from orbit suffers far less from atmospheric distortion effects than vice versa. Far better to put the telescope in orbit and send digitized image data to the ground.


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