APEX image calendar, May 2010 — APEX antenna at 5,104 m

The antenna of APEX, the Atacama Pathfinder Experiment telescope, looms over the hills of the Chajnantor plateau in Chile's Atacama region, approximately 5,100 metres above sea level. APEX is the largest submillimetre-wavelength telescope operating in the southern hemisphere, observing the cold and distant Universe for astronomers.