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This question originally appeared on Quora. Answer by Skip Morrow.

I would start with a few of my personal favorites (too bad the gov is shut down, or I could link to high-res photos from NASA directly)

#1. Here is Bruce McCandless during an EVA.

eva
Here is Bruce McCandless during an EVA. Quora

#2. Then of course, "Earthrise"

earthrise
"Earthrise." Quora

#3. I absolutely love this photo

blast off
I absolutely love this photo. Quora

#4. This one isn't much to look at, but when you realize it is one of the first photos taken by the Mars Science Laboratory (MSL) Curiosity on Mars, then it is pretty awesome.

mars
One of the first photos taken by the Mars Science Laboratory Curiosity on Mars. Quora

#5. I am a real sucker for pretty much any photo taken by Cassini orbiting Saturn.

saturn
A photo taken by Cassini orbiting Saturn. Quora

#6. Here is a picture taken not by NASA, but by an amateur astronomer. This is the ISS passing in front of the sun during a solar eclipse. I present to you "Transit of the International Space Station (ISS) during the Solar Eclipse of Jan 4 2011 from Oman" by Astrophotographer Thierry Legault.

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Solar eclipse of Jan. 4, 2011 from Oman" by Astrophotographer Thierry Legault. Quora

#7. Finally, to put it all in perspective, the Hubble Ultra-Deep Field. The light from the galaxies in this photo has been traveling for 14 billion years to reach us.

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The light from the galaxies in this photo has been traveling for 14 billion years. Quora