As part of the Atacama Large Millimeter/sub-millimeter Array’s (ALMA) inauguration week, This is Chile voyaged high up into the northern Atacama Desert to witness the groundbreaking ceremony. For more in-depth information about ALMA and the inauguration, check out our first piece on the event.
On Thin Air…
As the bus slowly ascended the dirt track to ALMA’s Array Operations Site (AOS), I found myself reading the same line of text on an inauguration pamphlet three times. Not because it was particularly fascinating; we were approaching 16,500 ft (5,050 m) altitude, and my oxygen-starved brain was moving in slow motion.
Sucking on one of the personal O2 tanks provided, I disembarked and walked past ALMA’s impressive array of antennas – constructed under a European, North American, and East Asian joint venture – and entered the AOS, the world’s second highest altitude building.
Directed down a corridor, we were greeted by Chilean electrical engineer Alejandro Saenz outside the temperature controlled rooms of the ALMA Correlator – a 170 kilowatt supercomputer.
«Think about the laptop you have at home,» Saenz said, wearing an oxygen tube wrapped under his nostrils, as is required of all AOS staff. «Now add three and a half million more laptops to it. That’s how powerful the Correlator is.»
The ALMA Correlator is responsible for receiving data from the antenna and sending it to hard-drives in the data archive at the Operations Support Facility (OSF), 2,150 m down the mountain, where the data can then be imaged by astronomers.
«When operating at full strength, the Correlator can transmit data at 1 gigabyte per second,» Saenz said. «From my perspective as an electrical engineer, this has been a huge opportunity, and I can see that for Chilean astronomers it’s a luxury to have this amount of time dedicated to their study.»
Saenz refers to the 10 percent of all ALMA viewing time that is afforded to Chilean astronomy departments, a condition compulsory to any foreign astronomy operation wishing to utilize northern Chile’s ideal observation conditions.
Downhill at the OSF, Charles Blue of the National Radio Astronomy Observatory (leader of the North American component of ALMA) highlighted why Chile was chosen as the site of the biggest ground-based observatory ever conceived.
«The Atacama is not only perfectly suited for astronomy, with its altitude and low humidity – it’s also such a vast area,» Blue told me. «This allows for such expansive operations. We are enabled, with very few constraints, to do whatever we can to achieve the best results.»
«We are starting to see those results now,» Blue continued, «though come back in ten years time and the original goals set for ALMA will have transformed, and we’ll be looking at things that right now we couldn’t imagine. The universe is always more mysterious, creative, and exciting than we can conceive, and ALMA will continue to solve and add to those mysteries.»
Life and Planets
As well as probing the edges of the universe, ALMA has already contributed both to the search for pre-biotic molecules in outer space and our understanding of the birth of planets.
Space is known to host a wealth of complex molecules, though many of those molecules cannot survive in the bright and hot regions of the cosmos observable from telescopes using optical light. ALMA is well suited for hunting down these molecules within the cool dust clouds in which they combine and reside. Already, ALMA has found sugar molecules in the clouds surrounding a sun-like star – an altogether new discovery – and scientists are confident ALMA will contribute further to our knowledge of the formation and behavior of the building blocks of life.
Our understanding of planet and star formation also stands to benefit from ALMA. Recently, the array produced astounding images of a rotating dust cloud acting as a cradle to a growing star and set of planets.
«ALMA can help us determine what dictates the mass of a star as well as how planets are formed,» astronomer Ewine van Dishoeck said. «It will also help us in one of the hot topics in astronomy; the detection of exoplanets.»
«This project has taken twenty years to complete,» van Dishoeck went on. «Now in such a short time it has revealed so much. We are so excited by the quality of the first data, we have been amazed at what we’ve found.»
By Angus McNeice
The ALMA Partnership consists of the European Southern Observatory (ESO), the National Astronomical Observatory of Japan (NAOJ) and the National Radio Astronomy Observatory.