[frownie]

I've looked at the zommable picture. When I zoomed to the maximum, I saw a lot of noise in the picture (and a arather regular one). Does it mean that although the resolution is pretty impressive, the noise make it less "useful" ? Just asking, I've 0 knowledge in this area.

Second question, just out of curiosity, would it be possible to look at closer objects like Mars or the moon ? We'd have a pretty good image too ?

[Betelgeuse90]

About the Mars question, consider the fact that the Andromeda galaxy, although faint in the sky, takes up 5 times more room in our night sky than the moon does. It's really huge.

Mars in comparison is minuscule in our night sky. It's just a tiny blob of light.

[andyjohnson0]

"..the Andromeda galaxy, although faint in the sky, takes up 5 times more room in our night sky than the moon does."

Correct, although wikipedia says 6 times and adds a clarification:

"Although it appears more than six times as wide as the full Moon when photographed through a larger telescope, only the brighter central region is visible to the naked eye or when viewed using binoculars or a small telescope." [1]

[1] http://en.wikipedia.org/wiki/Andromeda_Galaxy

[gambiting]

It was explained quite well recently - Hubble can't look at the Moon(or the Earth for that matter) because it's moving way too fast relative to either of these two bodies to take a non-blurry picture.

[BrandonMarc]

Randall Munroe took the question as part of his What If series.

https://what-if.xkcd.com/32/

Earth - Hubble is moving too fast to get decent close-up imagery, the distance is too small, and frankly Hubble just wasn't designed for it (as opposed to spy satellites of the major powers). Hubble does use the earth to calibrate its cameras, though.

Randall gives examples of how imagery might turn out.

Moon - speed's an issue, but less so, especially if you're imaging a large region

Here's an example: http://hubblesite.org/newscenter/archive/releases/2012/22/

Mars - Hubble has targeted this planet lots of times.

Some examples: http://hubblesite.org/gallery/album/solar_system/mars/

[pygy_]

No knowledge either, but it looks to me like the "noise" is actually made of stars.

Maybe you didn't zoom far enough? At sub-maximal zoom, there is aliasing resulting from a lack of low pass filtering before the resolution reduction. That looks a bit like sensor noise.

[lmm]

I certainly remember Hubble taking pictures of the moon. A quick google found http://www.nasa.gov/vision/universe/solarsystem/hubble_moon....

[Rooster61]

That isn't noise. Our own galaxy looks similar to that when looking at it in person with a telescope. This is a truly incredible image.