By Iñaki Martinez Azpiroz
Atacama, Chile (EFE).- The ALMA radiotelescope, the largest such instrument in the world and located at an altitude of 5,000 meters (about 16,250 feet) above sea level in Chile’s Atacama Desert, has now been in operation for 10 years during which time it has unveiled numerous secrets of the heavens, including taking the first photograph of a black hole.
In the arid altiplano where only thorny plants grow in the rocky soil, dozens of gigantic white metal structures dot the landscape, slowly moving their enormous round dishes in unison to gaze upward in different directions: these are the 66 detectors or antennas of the Atacama Large Millimeter/submillimeter Array (ALMA) which comprise the world’s largest telescope.
During its first decade of observations, ALMA has advanced scientific knowledge of the creation of new planets, the potential origin of life in other parts of the universe and even supermassive black holes.
“We can set the antennas in different positions, such that we can expand the telescope or make it more compact, according to our scientific needs. If we move them apart, we get more detail, but less amplitude in the image, and vice versa, like the zoom on a camera,” the communications coordinator for the observatory, Nicolar Lira, told EFE.
The signals that the ALMA dishes collect are combined using a supercomputer, which applies mathematical models to the data to obtain a unique image incorporating all the individual dishes’ observations.
ALMA has been made possible thanks to the joint work of about 20 countries – including the United Stattes, various European nations, Japan and Chile – a collaborative effort that also exists among several big observatories located at different points around the globe and which make possible unique astronomical discoveries.
Frequently, ALMA works with other observatories all around the planet, connecting their signals to create an enormous telescope the size of the Earth, the head of the ALMA science department, Elizabeth Humphreys, told EFE.
That was how, for example, the first photo ever taken of a black hole was made, by combining the signals of different observatories around the planet and creating the equivalent of a telescope thousands of miles in diameter using the same technology that ALMA uses to merge the signals from its 66 antennas and known as interferometry.
Observing a black hole from the Earth is “equivalent to looking from Spain into the little hole of a ballpoint pen located in Chile,” one of the ALMA astronomers, Hugo Messias, told EFE.
“Without international cooperation, it would have been impossible to achieve that,” he added.
ALMA was a revolutionary instrument for astronomy a decade ago, but the scientific community is already working on even larger telescopes to expand even farther the frontiers of knowledge that the Chilean observatory has been able to establish.
“Science is not black and white, but rather it advances bit by bit. There’s always something beyond what we know and human curiosity is practically infinite. With ALMA, human curiosity is not over yet,” Lira said.
Nevertheless, ALMA is preparing for a thorough renovation of its operating systems by 2030. The supercomputer will be replaced, along with several of the components of its antennae, to make the observatory’s work easier and increase the clarity of the data it collects.
One of the Chilean observatory’s strong points is its ability to capture information about the chemical components of the universe, Humphreys said, and the improvements to its components will increase that ability.
What the ALMA team wants to find is more information about the “chemistry of life” and to determine which star systems might harbor some kind of life, she said.
But science, if it is characterized by anything, must delve into the unknown, and Humphreys asked rhetorically what she wants to find in the coming years, answering her own question by saying “Surprises.”
She said the ALMA team is gathering data from many different projects and sometimes they don’t know what will come from all those collection efforts, but she loves discovering things that you could never have imagined.