And your first telescopes saw something large running up and down the tree?

Replies: Astronomers use telescopes to see things far away - does that answer the first question?

Since dark matter is invisible, how can an optical telescope see it?

From any particular place such events occur almost every night, although most require a telescope to see.

Up here in space, our telescopes can see all the radiation to better understand the universe.

Though our telescopes can now see to the limits of space, no man has yet traveled beyond Pluto.

They could not be told apart by radar, and telescopes couldn't see them at all.

On the evening of January 3 the telescope saw "first light" - and they found that the instrument couldn't be focused.

The telescope saw first light in 2012 and it was fully operational that year.

In the sky, a telescope can see the signs of metals and then the astronomer knows that there are stars.