If the Hubble can see a billion years back in time,why can't it see the moon lander?

Answer 1

Any mirror has a smallest angular size that it can resolve. For the Hubble scope, that resolution is about .014 arc seconds in the ultra-violet (larger in the visible range). This, by the way, is a theoretical limit. The distance to the moon is about 240,000 miles. At this distance, the smallest thing that the Hubble could see would be about 86 feet across. That's why we can't see the moon lander-we can't resolve it.

In contrast, the things billions of lightyears away are *huge* and actually have a larger angular size than the lander on the moon does. That is why we can resolve galaxies at those distances. For example, at the distance of 2 billion lightyears, Hubble can separate things that are only 135 lightyears apart. Since galaxies are hundreds of thousands of lightyears across, that isn't a problem. This neglects relativistic effects which do affect things at this distance, but you get the idea. A galaxy that is 100 thousand lightyears across and 2 billion lightyears away appears larger than the moon lander at 240 thousand miles away.

Answer 2

Because it is too close.

The Hubble was designed to look at objects light-years away from the Earth. Sure, it can be pointed to look at the moon, but it cannot focus at something that small for a clear picture, just like a far-sighted person has trouble focusing on objects that are close up. There have been some pictures from Hubble of the landing sites on the moon, but no details of the LEMs can be seen.

The far-sighted person needs corrective lenses to help him/her focus on the close-up, like reading glasses. The Hubble has a corrective lens installed that helps it see far away, since its original lens was ground to the wrong specifications when it was assembled here on Earth. But the cost of a corrective lens for its "far-sightedness" and the cost to install it are vastly more than the benefit that would be derived from having it.

Answer 3

The billion years means it sees light emitted from a light source a billion years ago.

Light travels at a very high, but still limited. speed. It means that light from something very far away will take a very long time to get here. This light will not change too much, so the image the light carries is an exact copy of what happened when it was made, maybe a billion years ago. Then it took 1 billion years to reach us here on earth. This, in effect, lets us see what happened at that point in space at that particular time.

Answer 4

It sees that far back in time by looking at things far far away. The closer things are the more they appear like they are today. If you look 4 billion light years away, you see what was happening 4 billion years ago.

Answer 5

Because the Moon landings happened only 37 years ago?

Answer 6

the hubble space telescope has an angular resolution of about 0.05 arc sec. at the distance of the moon, the hubble space telescope can not see anything less than about eighty meters across.

look here:
http://apod.nasa.gov/apod/ap020628.html

Answer 7

It might be able to, if you could somehow instantly move it far enough away and look back at the moon. You'd have to move it far enough away so that the light from that time had not reached there yet.

Answer 8

Cause some alien took it home for their museum.

Answer 9

That light has already come and gone.