A giant ground-based telescope with a mirror up to 60 metres wide is being planned by the European Southern Observatory. The telescope would be able to detect Earth-like planets around other stars and spot the universe鈥檚 first galaxies.
The ESO has created a new office to design the European Extremely Large Telescope (E-ELT). 鈥淓SO aims to put the E-ELT on a fast track,鈥� says Roberto Gilmozzi, the principal investigator for the project.
Project managers have not yet chosen the size of the mirror but say it could range from 30 to 60 metres wide. ESO had previously been considering a 100-metre telescope called the OverWhelmingly Large telescope (OWL). But a review of the concept concluded that the project would be too risky and would take too long to build, Gilmozzi says.
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鈥淭he advice was to go for a smaller telescope so that there was less risk and so it could be built in a shorter time,鈥� he told 快猫短视频.
International partnerships
Their goal is to build it for 聙750 million ($950 million) and have it ready to observe by 2015. Gilmozzi says ESO will likely provide about half the funds needed, with more coming from individual ESO member countries. Other funds could come from possible partnerships with non-European countries like the US or Japan, he said.
Two other groups are also pushing forward with plans for giant telescopes. A US-Australian consortium is planning a 24.5-metre instrument called the Giant Magellan Telescope (GMT) to be built by 2016 (see World鈥檚 largest telescope begins with a spin). And a US-Canadian group is planning the Thirty Meter Telescope (TMT), also to be built by 2016.
The huge mirrors used for these projects will be assembled from smaller segments. 鈥淭hat鈥檚 way cheaper than trying to build a single big mirror,鈥� says TMT team member Ray Carlberg of the University of Toronto, Canada.
The other crucial ingredient is a technology called adaptive optics, which compensates for the way light is blurred by Earth鈥檚 atmosphere. This involves bouncing light from the telescope off a small corrector mirror, whose shape can change to counteract atmospheric distortion.
New vistas
While space-based telescopes enjoy crystal-clear views, ground-based telescopes have their own advantages. 鈥淔or a given budget, ground-based telescopes can be much larger than telescopes in space,鈥� says GMT project manager Matt Johns of the Carnegie Institution of Washington鈥檚 Observatories in Pasadena, California, US.
The giant ground-based telescopes will have vision roughly four times sharper than the James Webb Space Telescope (JWST) that will replace Hubble, he says.
That powerful vision should open new vistas for astronomy. 鈥淭he TMT, along with other telescopes, is largely going to figure out how galaxies form, how stars form and how planets form,鈥� says Carlberg.
As supporting technology such as adaptive optics improves, the new telescopes could eventually analyse the gases in the atmospheres of other Earth-like planets.
鈥淎lmost everyone is really excited about this planet stuff,鈥� Carlberg told 快猫短视频. 鈥淭here鈥檚 a whole vast new area of discovery there.鈥�
