Image Credit & Copyright: European Southern Observatory (ESO) Babek Tafreshi.
I can’t get enough of these ALMA images. Behind the closest antenna, the Milky Way galaxy rises vertically overhead and off in the distance like two snowballs on a glass window is the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC); satellite galaxies to our home star city. ALMA’s antennas, bathed in green light from the positioning lights from other antennas, over watch the scene unfolding above them every night.
What Is ALMA?
Located 5058 meters (16,597ft.) high on the Chajnantor Plateau in the Atacama Desert, Chile (The driest desert in the world) sits the most powerful radio telescope as well as the most expensive ground based telescope ever created. The Atacama Large Millimeter/Sub-millimeter Array or “ALMA” as it’s called is an interferometer of radio telescopes (66 massive 12 meter and 7 meter radio telescopes to be precise) that work at millimeter and sub-millimeter wavelengths. The entire array stretches a mind blowing 10 miles in diameter and has a resolving power 5 times finer than Hubble and 10 times finer than the Very Large Array (VLA) in New Mexico, USA.
Interferometry is, in short, the collection of different telescopes working together to attain a higher resolution on a given object in the universe. Also, sub-millimeter astronomy is radio astronomy conducted at wavelengths longer than radio waves and shorter than visible light waves.
ALMA is a member of the European Southern Observatory and is a collaboration between European Nations, United States, Canada, East Asia as well as the Republic of Chile. Its main goal is to peer through material in molecular clouds and study regions of new star formation, stellar evolution, stellar death, planetary systems, galaxies as well as the origins of life itself. It is the highest ground based observatory on Earth and its correlator supercomputer is the fastest ever used at an astronomical site.
On site you will also find the Atacama Compact Array (ACA) which is a subset of 16 radio telescopes (12-7 meter antennas and 4-12 meter antennas) designed to observe large angular size objects such as close galaxies and molecular clouds.
ESO page for this image: https://www.eso.org/public/usa/images/ann13002a/