Chile’s Pristine Skies Are Key To Astronomy’s Next Generation Of Telescopes

by Benice BurgerFebruary 12, 2018

Long known for its copper, sea bass and merlot wine, Chile’s most profound export may be data that its astronomical observatories mine nightly from its pristine skies.

Credit: ESO
Exoplanet hunters at ESO’s La Silla Observatory in Chile.

Because Chile’s ground-based window onto our Milky Way’s galactic center is arguably unmatched, the European Southern Observatory (ESO) first set up shop here more than a half century ago. Today, their 15 member states enjoy facilities at three major observatories.

“ESO spends 80 million euros [$100 million] a year for its operations in Chile and is the biggest astronomical operation here,” astrophysicist Fernando Comeron, ESO’s Representative in Chile, told me during a recent visit to ESO’s offices in Vitacura, a tony enclave of Santiago.

To its credit, ESO never rests on its laurels. When I first arrived here two decades ago during research for my book “Distant Wanderers,” I was amazed that even before ESO’s Very Large Telescope (VLT) was finished, there was already talk of the next big thing.

Initially, that next big thing was to be a 100-meter Overwhelming Large Telescope (OWL). But after several years of study, ESO put that concept in stasis and instead pursued a project that it felt was more practical and technologically feasible. Thus, in 2014, ESO broke ground for its European-Extremely Large Telescope (E-ELT) at Paranal Observatory in northern Chile’s Atacama desert.

Due for scientific first light in November 2024, once completed it will be the world’s largest optical/infrared telescope. That is, a $1.4 billion behemoth with a 39.3-meter primary mirror; itself a composition of 798 individual 1.4-meter segments.

The best telescopes in the world are now in the Southern hemisphere , says Comeron, noting that the Chilean government takes its responsibility in preserving observing conditions very seriously. In fact, he says, even through the country’s turbulent political history, ESO continued to function here.

“We have 50 years of dealing with the Chilean government and it’s been a very fruitful relationship and is not subjected to changes of government or politics,” said Comeron.

Credit: Francisco Rodriguez Irigoyen/ESO.
Fernando Comeron, the European Southern Observatory’s Representative in Chile, and author at ESO’s Santiago offices.

And more are coming. The E-ELT and other new telescopes being built in Chile, like the Large Synoptic Survey Telescope (LSST) and the Giant Magellan Telescope (GMT), are forever changing the Chilean astronomical landscape.

“The Chilean astronomy community is growing; universities are opening undergraduate and graduate programs in astronomy and attracting international researchers to be part of their institutions,” Barbara Rojas-Ayala, an astronomer at the Universidad Andrés Bello in Santiago, told me.

What makes Chile so astronomically special?

Very dry northern deserts which border a lengthy coastline and the Humboldt Current.

The Humboldt Current, sometimes referred to as the Peru Current, is a 550-mile-wide cold ocean current that originates in Antarctica and runs north along the South American coastline. Its temperatures help keep Chile’s northern desert air even drier. Cloud cover is confined to altitudes of about 3000 feet, says Comeron.

As a result, he says you find very dry conditions at much lower altitudes in Chile. But it’s also why despite Chile’s thousands of miles of extraordinarily beautiful coastline, the country is not known for beach-life.

“The water is even freezing in summer,” said Comeron.

What will the E-ELT bring to the table?

The ability to see earth-like planets at one Earth-Sun distance from their star to look for the spectroscopic signatures of life.

And Comeron predicts the E-ELT will give astronomers at least some spectra that will be debated as containing biosignatures.

In terms of cosmology, the new telescope should also shed light on:

— Whether the laws of nature are truly universal;

— Individual stellar populations within galaxies out to distances of tens of millions of light-years; and,

— Observe back in cosmic time to before the onset of the first stars which will help astronomers determine how galaxies formed and evolved across the breadth of the cosmos.

Credit: ESO/L. Calçada
Artist’s impression of the European Extremely Large Telescope (E-ELT) in its enclosure on Cerro Armazones, a 3060-metre mountaintop in Chile’s Atacama Desert. The 39-metre E-ELT will be the largest optical/infrared telescope in the world. Credit: ESO/L. Calçada

And as for the burgeoning Chilean astronomy community?

“Chile is on the way to becoming a net producer of astronomers with more going abroad than staying here,” said Comeron. “For ESO, we have about 600 astronomers coming here per year.”

However, Comeron says a few thousand astronomers per year use all of Chile’s facilities.

Considering all the data that will be acquired with observatories within our country, there is a lack of funding for local researchers who could data-mine these large astronomical projects, says Rojas-Ayala.

But like almost everywhere else on the globe, Chile, too, suffers from light pollution. In central Santiago, Rojas-Ayala says it’s impossible to distinguish the Milky Way and the Magellan Clouds. As a result, she says there are now initiatives to restrict blue light emissions and luminous LED/plasma signs in an effort to protect northern Chile’s precious night skies.

As for the E-ELT’s ultimate legacy?

It has a nominal operating lifetime of at least 30 years. But Comeron expects it will still be operational well into the 22nd century and although astronomers have some ideas about what this new behemoth will observe in its first few years, beyond that it’s anyone’s guess.

“It’s almost science fiction as to what we will be observing,” said Comeron. “I haven’t a clue but it’s going to be exciting.”

 

Source: https://www.forbes.com/sites/brucedorminey/2018/01/31/chiles-pristine-skies-are-key-to-astronomys-next-generation-of-telescopes/#d8620ef2dcf8

About The Author
Benice Burger