Giant Magellan Telescope to navigate skies as it gets go-ahead

3 Jun 2015

Concept image of GMT via GMT

Distant space could be about to get an awful lot clearer after the Giant Magellan Telescope (GMT), one of the largest telescopes ever conceived, was given the go-ahead to begin construction in Chile.

Expected to cost about US$500m, the GMT’s site will be at the Las Campanas observatory, where nearly 2,500 cubic metres of rock have already been removed to make way for the super-structure.

According to the BBC, the area needed for the GMT will be the equivalent of four football pitches and it will be comprised of seven 8.4m mirrors that will allow the telescope to potentially see the furthest reaches of the universe, in a bid to understand how the universe was born.

Chile is something of an astronomer’s playground due to its high mountains and clear skies, with Europe’s Extremely Large Telescope (ELT) already based there.

The GMT expects to begin operations in a limited capacity in 2021 with full operations expected to commence by 2025 at the latest.

The GMT's mirror array

The GMT’s mirror array. Image via GMT

Largest optical telescope on Earth

Speaking to the BBC, the GMT’s director, Pat McCarthy, said: “”We expect in late 2021, possibly in early 2022, we will put three or four primary mirrors in the telescope, start doing some engineering, start doing some astronomy, and by that point we will have the largest (optical) telescope on the planet by a good margin.

“We’ll then slowly integrate the rest of the mirrors as they come along so that by 2024 or 2025, we should have all seven mirrors in the telescope.”

By having seven large mirrors instead of hundreds as used by other telescopes like the ELT, McCarthy believes it will offer a much clearer picture, perhaps 10-times clearer than the Hubble Space Telescope: “We think there is great advantage in having as much of your collecting area as possible in a contiguous, uninterrupted optical surface.”

Colm Gorey was a senior journalist with Silicon Republic