ALMA

One of the most remarkable objects that’s visible to the unaided eye stands well up in the south-southeast as night falls: the Orion Nebula. It looks like a small, fuzzy patch of light below the three stars of Orion’s Belt. Yet it’s really a spectacular stellar nursery - a complex of thousands of newborn stars, plus the gas and dust for making many more.

The nebula is a prime target for a new telescope that’s being dedicated today in Chile. It’s called ALMA - the Atacama Large Millimeter-Submillimeter Array. When it’s completed, it’ll consist of 66 large radio dishes scattered across a three-mile-high plateau in the Andes Mountains. A supercomputer will combine the signals from the dishes to produce images and other observations of a variety of astronomical objects.

Many of those objects involve gas and dust, which glow brightly at ALMA’s wavelengths. The list of targets includes stellar nurseries like the Orion Nebula, star systems where planets are taking shape, and the gas clouds