Since the first modern telescope was constructed in the early twentieth century, these vital instruments have slowly but steadily increased in size. From the first 1.5-meter telescope in 1908 to the 5.1-meter Hale telescope constructed in 1949 to the 10-meter Keck mirrors in 1993, progress has been steady. Advances in modern engineering, however, are poised to accelerate this pace as never before. The first of these so-called Extremely Large Telescopes will be the Thirty Meter Telescope (TMT).
This week the TMT, a partnership spearheaded by the University of California, Caltech, and the Association of Canadian Universities for Research in Astronomy, received vital approval from the natural resources board of Hawaii. This might not seem like a big deal - after all, the top of Mauna Kea appears as dead as the surface of the Moon - but this approval is often one of the most challenging steps in constructing a new observatory. The reason lies in the cultural heritage of the native Hawaiian peoples. The summits of the large Hawaiian volcanoes are among the most sacred locations for these cultures, who see them as the doorway to the afterlife. Virtually any construction threatens a religious or spiritual site. Additionally, the peak is home to at least one rare species of Hawaii's already remarkable ecosystem.
In their ruling, the board placed numerous restrictions on the conduct and training of construction workers, engineers, and scientists at the site. Such conditions are a virtual necessity on Mauna Kea.
If it's so much trouble to build there, why do we bother? The answer lies in Hawaii's unique geography. Mauna Kea, which punches more than 4000 meters out of the Pacific Ocean, is one of the clearest and driest places on Earth. Driving to the summit passes you through nearly all the layers of clouds which would obscure the stars and blur observations. In addition, its location in the middle of the Ocean and the fact that the Big Island has few towns or cities means that light pollution isn't a major problem. Perhaps the only better site in the world is the high deserts of Chile's Atacama desert, half a world away.
So what will building the Thirty Meter Telescope net astronomy? With nine times the collecting area of any other telescope on Earth, the TMT will allow astronomers to peer further back at fainter objects than ever before. Its advanced adaptive optics system, which automatically corrects for distortions in the atmosphere, will allow it to capture images that are ten times sharper than the Hubble Space Telescope and more than a hundred times sharper than many current research telescopes. Using this incredible resolution, it should be able to stare down exoplanets like never before.
With this legislative hurdle passed, construction of this amazing facility will hopefully begin within the year. At a cost of over $1 billion, this will be no small feat. But, when the observatory opens in five or six years, that will undoubtedly feel like money well spent.