Astronomy / Space Our home planet, as seen from Mars

[Shadowdancer]

Getting away from the whole perspective thing for a moment - I have just looked at the image in wonder and showed my other half who greeted with a "yeah and". That image is taken from Mars!!!!!

And it still frames all of humanity, and all but a small handful of all our achievements too.

 

[NeilF]

… and view them from about 4.5km away in this case. Foreshortening is relative to the difference in object distance in relation to their distance to the observer.

Sorry you've lost me there?

The point being made is if the image in question had been taken X days earlier/later it would have given a better perspective on the true distance of the moon from the earth. (Although the outcome wouldn't have fitted in a single image very well!)

ie: It would have looked more like this (very roughly)

Are we talking at cross purposes maybe?


Note how the original image doesn't give a very good indication of the "true" distance the moon is from the earth?

- - - Updated - - -

Getting away from the whole perspective thing for a moment - I have just looked at the image in wonder and showed my other half who greeted with a "yeah and". That image is taken from Mars!!!!! It is not a representation it is not an artists impression it is something made by man showing the planet of his birth from its sibling planet.

And when it's taken from a camera held by a human, then we can really start cheering

 

[Shadowdancer]

The point being made is if the image in question had been taken X days earlier/later it would have given a better perspective on the true distance of the moon from the earth. (Although the outcome wouldn't have fitted in a single image very well!)

And that's what the article states too:

"the observation was planned for a time at which the moon was almost directly behind Earth, from Mars' point of view, to see the Earth-facing side of the moon"

Taking the shot at another angle would have been pointless since the earth-facing side of the moon was a calibration target in this shot.

 

[NeilF]

And that's what the article states too:

"the observation was planned for a time at which the moon was almost directly behind Earth, from Mars' point of view, to see the Earth-facing side of the moon"

Taking the shot at another angle would have been pointless since the earth-facing side of the moon was a calibration target in this shot.

Aha!!

 

[starsphinx]

And when it's taken from a camera held by a human, then we can really start cheering

Actually even when we are on Mars we will not be taking this shot - it will require a camera attached to a very large telescope. A human might press a computer key to capture the image but that is pretty much what happened here anyway. I guess the difference would be the person would be there looking through the telescope rather than depending on images beamed across space.

 

[Shadowdancer]

it will require a camera attached to a very large telescope.

In this case, a 12m focal length f/24 instrument in orbit.

 

[NeilF]

Actually even when we are on Mars we will not be taking this shot - it will require a camera attached to a very large telescope. A human might press a computer key to capture the image but that is pretty much what happened here anyway. I guess the difference would be the person would be there looking through the telescope rather than depending on images beamed across space.

Fair point... But you get my gist none the less

 

[Para Handy]

You don't get much of that at the distances involved; the diameter of the Moon's orbit is around 3‰ of the distance the image was taken at (205000Mm vs. ~750Mm), so the relative size between Earth and Moon would be fairly independent of the Moon's position.

You are quite correct - I have suffered a brain fade from interrupted sleep I think. Anywayup, Father Ted is still funny. (RIP)