APOD 4.5

APOD 4.5
3 ATs
2012 April 21

 When my eyes read the title, my mind jumped immediately to AT-ATs and Star Wars. Yuri Beletsky warns readers that these R2D2 look-alikes are "not the droids" we're looking for. While not as interesting as a sentient repair robots or All Terrain Armored Transports, these Auxiliary Telescopes do serve a greater purpose; they gather light into a common focal point to act as a interferometer. The three Auxiliary Telescopes are on tracks and shift with another (off camera) telescope to gather enough light for higher resolution stargazing. The picture above was taken in Chile's Paranal Observatory, which makes sense since the Large and Small Magellanic clouds are visible in the southern hemisphere.