Explanation

Braun was a German-born American aerospace engineer and space architect. 

Explanation

Periscopes allow a submarine, when submerged at a relatively shallow depth, to search visually for nearby targets and threats on the surface of the water and in the air.

When not in use, a submarine's periscope retracts into the hull.

Explanation

A lunar eclipse occurs when the Moon moves into the Earth's shadow.

This can occur only when the Sun, Earth, and Moon are exactly or very closely aligned with Earth between the other two, and only on the night of a full moon.

Explanation

Light rays from the sun appear to the naked eye as white light, but each ray contains a broad range of wavelengths

Explanation

The geographic grid refers to the internationally-recognized system of latitude and longitude used to location positions on Earth's surface.

Explanation

The Brooklyn Bridge is the southernmost of four toll-free vehicular bridges connecting Manhattan Island and Long Island, with the Manhattan, Williamsburg, and Queensboro bridges to the north.

Explanation

LBOD project was to bring drainage effluents from the upstream and dispose it of into the Arabian Sea, via the Tidal Link Canal

Explanation

Explanation

The German passenger airship  Hindenburg caught fire and was destroyed during its attempt to dock with its mooring mast at Naval Air Station Lakehurst.

Explanation

The Arctic Circle is one of the two polar circles and the most northerly of the five major circles of latitude as shown on maps of Earth.