From an altitude of over 5,000 meters, the night sky view from Chajnantor Plateau in the Chilean Andes is breathtaking in more ways than one. The dark site’s rarefied atmosphere, at about 50 percent sea level pressure, is also extremely dry. That makes it ideal for the Atacama Large Millimeter/submillimeter Array (ALMA) designed to explore the universe at wavelengths over 1,000 times longer than visible light.
via APOD








