On Thursday 27 March, the European Space Agency (ESA) sent its last messages to the Gaia Spacecraft. They told Gaia to shut ...

Small instruments – whether for amateur astronomers starting ... while telescopes flown aboard balloons or aircraft need to be compact. Although reflecting telescopes can be much lighter than ...

Reflecting or reflector telescopes utilise a single mirror or ... the light from the main or 'primary' mirror is deflected by a small flat secondary mirror, set at such an angle that it is sent ...

He reached a point of diminishing returns beyond which enlarging the image made what was seen through the telescope too small to be of ... was the first working reflecting telescope.

Radio telescopes are one of the more high-profile pieces of scientific apparatus. There is an excitement to stories of radio astronomers of old probing the mysteries of the Universe on winter ...

The favored scheme was an array of relatively small dishes (antennas), with a nearly-random ... ground surrounding the telescope. Moving the reflector assembly off-center minimizes the chance of ...