A blood Moon over ESO’s Headquarters

After nightfall on 15 June 2011 in Garching, near Munich, Germany, a blood-red Moon rose above the horizon. This striking phenomenon was caused by a total lunar eclipse in progress at moonrise, and it was captured in the skies over the European Southern Observatory’s Headquarters.

A lunar eclipse takes place only when the Moon, Earth and Sun are exactly aligned. When the Moon passes through the shadow cast by the Earth, our planet blocks the path of direct sunlight to the lunar surface and a total eclipse occurs. This event can only happen on the night of a full Moon.

Unlike the better known solar eclipses, the Moon doesn’t completely disappear from sight during a total lunar eclipse. Instead it appears painted blood red, giving it the ominous nickname of “blood Moon”. The reddish colour is caused by scattered sunlight that has passed through the Earth’s atmosphere — the same effect that causes sunsets and sunrises to turn the sky a reddish colour.

Last week’s eclipse was rare in that it was the longest total lunar eclipse in more than a decade, lasting almost two hours. The year 2000 saw the last lunar eclipse lasting as long as this one, while the next won’t occur until 2018.

ESO’s Headquarters in Garching function as an administrative and technical centre for ESO’s operations, with astronomers from all over the world gathering here to carry out cutting-edge scientific research.