The Thirty Meter Telescope (TMT) - soon to be the world's widest eye on space - has got the go-ahead for construction on the summit of Mauna Kea, Hawaii. Most of Mauna Kea is below sea level. When measured from its oceanic base, its height is 33,500 ft (10,200 m)—more than twice Mount Everest's base-to-peak height. The sacred mountain is about one million years old --long past the most active shield stage of life hundreds of thousands of years ago--providing a stable platform for what will will be the world’s most advanced and capable ground-based optical, near-infrared, and mid-infrared observatory.
The resolution and sensitivity provided by its large aperture and adaptive optics systems, combined with a flexible and powerful suite of instruments, will enable astronomers to address many of the most fundamental questions ofthe coming decades.
One of the primary missions of the TMT will be the detection and analysis of life-bearing exo planets. The exoplanets that have so far been detected are gas giants like Jupiter and Neptune. They were found because their large mass noticeably perturbs the motion of the host star. Surprisingly, many are found very close to their host star. As the higher temperatures there would prevent such planets from forming, itseems that they must have migrated inward, after forming at greater distances. Most astronomers believe that smaller terrestrial planets exist, but these cannot be detected with present telescopes. The TMT will help answer such questions as are such planets common and can they survive the disruption that would result from migration of the massive planets? Do they have atmospheres like Earth?
If terrestrial planets exist, are conditions conducive to the development of life? Each star has a habitable zone, where a planet would have a surface temperature similar to that of Earth. If, as expected, exoplanetary systems have populations of small icy bodies like comets, it is possible that water and organic molecules could have been delivered to such planets by impacts. If life then develops, it might be detected by signatures of biological activity in planetary atmospheres.
Adaptive optics (AO) systems allow the largestoptical-infrared telescopes on Earth to achieve higher resolution than telescopes in space, which necessarily have smaller apertures. By compensating atmospheric turbulence, AO allows telescopes to reach the diffraction limit, in which the angular resolution achieved is proportional to the diameter of the telscope aperture.
The TMT will dwarf 13 other telescopes located on the extinct volcano --the biggest currently is the twin 10-metre Keck telescopes. The summit is a perfect location as it offers clear skies for 300 days of the year. The TMT will have to cede the world size record, when the European Southern Observatory's 39-metre European Extremely Large Telescope on the mountain Cerro Armazones goes live in Chile early next decade.
The Daily Galaxy via TMT