World War II era telemeters worked optically with two telescopes focused on the same target but a distance apart along a baseline.

The telescope focused on the Paravacini compound revealed the imposing yacht at the dock, behind it deserted lawns with none of the myriad fountains operating.

We spent most of it looking through the ship's telescopeactually, looking at screens showing us what the ship's telescope was focusing on.

Radiotelescopes focus radio radiation from celestial objects in much the same way that the collecting mirrors in optical telescopes gather and focus light.

In the transmitting phase, the telescope takes the concentrated laser beam, focuses it and fires it toward a particular reflector on the Moon.

Mr. Young, who keeps a telescope focused on the spot that caught the ranger's eye, invited him to take a look.

The two cameras can observe simultaneously thanks to a dichroic placed before telescope focus the same field of view of 10x10 arcmin.

During its first winter of operation, the telescope will also focus on something much closer to home - Earth's own atmosphere, and the ozone it contains.

The telescope focuses, but objects in the distance are not magnified and appear upside down.

But last week NASA announced a show-stopper: the telescope can't focus properly.