Question

When was the first picture taken outside our galaxy?

Answer 1

The first picture of the Andromeda galaxy - an object outside our own galaxy - was taken in about 1900.

It took until 1923 for it to be identified as lying outside our galaxy.

Explanation:

The first picture of the Andromeda galaxy was taken in about 1900 at the Yerkes Observatory. It was then thought to be some kind of nebula inside our own galaxy.

In 1923 Edwin Hubble used the Mount Wilson 100 inch telescope in California to take more pictures and determine that it was a separate galaxy.

To deduce this, he calculated the approximate distance of Andromeda using some Cepheid variable stars as being more than 10 times distant than anything in the Milky Way.

Incidentally, one of the most famous pictures taken by a man-made camera at great distance from Earth is the "pale blue dot" picture that Voyager 1 took of Earth from about 40 AU away on February 14th 1990. Voyager 1 is now about 140 AU away. That is approximately `0.002` light years.

In order to actually take a picture from outside our own galaxy would require a camera at least `1000` light years away (moving out of the plane of the galaxy). To get a camera there would take at least `1000` years, but probably much longer. It would then take another `1000` years for any pictures it transmitted to return to us.

Footnote

One of the early terms used for galaxies - once we realised that ours was not the only one - was "island universes". In one sense that old term seems very appropriate, since the distances between galaxies seem to preclude travel between them, thereby isolating them like islands. In another sense it gives a false picture in that much of the material in our galaxy is now thought to have come from other galaxies.