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An astronomer’s paradise — Chile

I just added another “big science” ground telescope to my Experiments page — the GMT. Astronomers claim that the images from these giant telescopes will be better than those sent to earth by the Hubble space telescope. Yet another in Chile. Then I recalled recently reading about Chile as an astronomer’s paradise. Here’s a sampling of articles:

• “Why Chile is an astronomer’s paradise” by Gideon Long, BBC News, Paranal Observatory, Chile (July 25, 2011) — “By some calculations, by 2025 the country will be home to more than half the image-capturing capacity in the world.”

With its crystal clear skies and bone dry air, the Atacama Desert in northern Chile has long drawn astronomers. Some of the most powerful telescopes in the world are housed here.

But now, work is about to begin on a telescope that will dwarf them all – not a VLT (Very Large Telescope) but an ELT (Extremely Large Telescope).

It will be built 2,600m (8.530ft) up in the Andes on a site overlooking the Paranal observatory, and when it is finished in 10 years’ time it will be the most powerful optical instrument in the world.

The telescope will be the size of a football stadium, cost around $1.5bn (£930m) and weigh over 5,000 tonnes.

• “An Astronomer’s Paradise, Chile May Be the Best Place on Earth to Enjoy a Starry Sky — Chile’s northern coast offers an ideal star-gazing environment with its lack of precipitation, clear skies and low-to-zero light pollution” by Govert Schilling, Smithsonian Journeys Quarterly (July 22, 2015)

As the famous American astronomer Carl Sagan once said: “Astronomy is a humbling and character-building experience.” The Chilean night sky touches your deepest self.

For professional astronomers, Chile will remain the window to the universe for many years to come. On Cerro Las Campanas, plans are in place to build the Giant Magellan Telescope, featuring six 8.4-meter (330 inches) mirrors on a single mount. Meanwhile, the European Southern Observatory has chosen Cerro Armazonas, close to Paranal, as the site for the future European Extremely Large Telescope (E-ELT). This monster instrument—which would be the largest optical/near-infrared telescope ever built—will have a 39-meter (128 feet) mirror consisting of hundreds of individual hexagonal segments. It is expected to revolutionize astronomy, and it may be able to detect oxygen and methane—signs of potential life—in the atmospheres of Earthlike planets orbiting nearby stars.

• Wiki > Astronomy in Chile

• NPR > “Chile And Telescopes Are A Match Made In Heaven” by Joe Palca — Heard on All Things Considered (August 2, 2019)

• > “Giant Magellan Telescope Project Finishes 2nd Primary Mirror” by Mike Wall (August 1, 2019)

The GMT is taking shape on a mountaintop in the Chilean Andes. The telescope will feature seven primary mirrors, which together will create a light-collecting surface 80 feet (24.5 m) wide. The powerful scope will allow astronomers to investigate some of the cosmos’ deepest mysteries — the nature of dark matter and dark energy, for example, and whether Earth life is alone in the universe.

The seven GMT primary mirrors are a marvel of engineering. Each one takes years to make, from the initial casting in a big, rotating furnace through multiple stages of grinding and polishing. The surfaces of the completed mirrors are perfect to within 25 nanometers — about 1 millionth of an inch.

GMT is one of three megascopes expected to come online in the mid-2020s. The Extremely Large Telescope will observe the heavens from Chile as well, whereas the Thirty Meter Telescope will be built on Hawaii’s Mauna Kea volcano.

Wow! The next decade will be even more amazing for astronomy.

One thought on “An astronomer’s paradise — Chile

  1. Chile’s ALMA in the news: “These Gargantuan Galaxies, Hidden in Plain Sight, Could Rewrite Universe’s Early Days” ( August 7, 2019).

    It’s the ultimate magic of science, when using a different instrument reveals what was hidden in plain sight.

    Because of their distance from Earth and the type of light they produce, they are invisible to the Hubble Space Telescope, which sees approximately the same types of light as our eyes do.

    Instead, the researchers turned first to data gathered by NASA’s Spitzer Space Telescope, identifying 63 previously unknown objects. But the team couldn’t quite make out what those objects were. So the astronomers turned to the Atacama Large Millimeter/submillimeter Array (ALMA), a spread of radio dishes in Chile. The instrument established that 39 of the objects were massive galaxies each producing huge numbers of stars, the equivalent of 1,000 of our suns every year.

    Also: > “Astronomers discover vast ancient galaxies, which could shed light on dark matter” by University of Tokyo (August 7, 2019).

    “It was tough to convince our peers that these galaxies were as old as we suspected them to be. Our initial suspicions about their existence came from the Spitzer Space Telescope’s infrared data,” said [researcher] Wang. “But ALMA has sharp eyes, and reveals details at submillimeter wavelengths, the best wavelengths to peer through dust present in the early universe. Even so, it took further data from the imaginatively named Very Large Telescope in Chile to really prove we were seeing ancient massive galaxies where none had been seen before.”

    Source: Nature > “A dominant population of optically invisible massive galaxies in the early Universe” (August 7, 2019).

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