Monster Telescope Takes Another Step Forward

Supersized. The E-ELT would be the largest optical telescope ever built.

European Southern Observatory

Building huge telescopes is hard. Funding them is even harder, it seems. The Council of the European Southern Observatory (ESO) today approved construction of the European Extremely Large Telescope (E-ELT)—which would be by far the biggest optical/infrared telescope in history. But the project still faces obstacles, as several nations still need to confirm their contributions to the €1.1 billion ($1.35 billion) instrument.

At its previous meeting in December 2011, the ESO Council approved preparatory work on the project, including the construction of a road to the summit of Cerro Armazones in northern Chile, where the telescope will be located. But today's vote was the first official approval of the full E-ELT program. In a press release, ESO Director General Tim de Zeeuw said, "This is … a great day for ESO."

With a segmented primary mirror measuring 39.3 meters across, the E-ELT will collect more starlight than all existing professional telescopes combined and reveal 16 times more detail than the Hubble Space Telescope. Equipped with a suite of cameras, spectrographs and other instruments, the telescope is expected to detect the very first galaxies in the early universe; study the birth, evolution, and death of stars and planets; and directly image habitable planets orbiting other stars. It could be up and running in the early 2020s.

But here's the small print: Of ESO's 14 member states, just six (Austria, the Czech Republic, Germany, the Netherlands, Sweden, and Switzerland) voted to officially commit to the project, which will require them to increase their annual membership payments by 2%. Four countries—Denmark, France, Portugal, and Spain—"are not yet in a position to commit and need more time, so they abstained from voting," says ESO spokesperson Lars Lindberg Christensen. The representatives of the remaining four member states—Belgium, Finland, Italy, and the United Kingdom—voted yes, but their support still needs to be confirmed by their ministries or governments.

The government of Brazil, meanwhile, has yet to ratify the country's ESO membership. Funding the E-ELT won't be possible without Brazil's entrance fee, planners say.

Despite the uncertainty, the E-ELT is in a better financial position than its two main competitors, the Giant Magellan Telescope and the Thirty Meter Telescope "The question is no longer whether the E-ELT will start or not, but now it is just a question of the timescale for the start of the biggest contracts," says Lindberg Christensen.

Meanwhile, work on the access road to 3064-meter-high Cerro Armazones (close to ESO's Paranal Observatory, which is home to the existing Very Large Telescope) will probably start later this year. Levelling of Armazones's conical summit, to make room for the huge instrument, may also begin. And opticians are already spending money on the first design phase of the E-ELT's complex mirror system.