May 27, 2020

07.06.10: Mega-Scope Site Selected.

The dawn of the mega-scopes is almost upon us… earlier last month, the European Southern Observatory (ESO) consortium announced a site selection for their whopping 42 meter monster; the E-ELT (European Extremely Large Telescope) which will be perched atop Cerro Armazones in central Chile. The 10,020 foot high summit beat out four other possible sites in Chile and the Canary Islands during the long site evaluation process due to its outstanding clarity and seeing. First light is projected to be 2018, and the E-ELT will be composed of a 1,000 hexagonal mirror segments bringing light to focus on a Nasmyth instrument platform.  While designers had to “settle” from designs that included scopes as large as the proposed 100-meter Overwhelmingly Large telescope (!) The E-ELT will still be four times as large as most single aperture scopes in use today. To give you an idea of its scale, the secondary mirror will be larger than the legendary Hale Telescope’s 200-inch primary! Such an engineering project will also pose crucial challenges to designers, as well as kick the “aperture envy” up among astronomers a notch…and like most new instruments, E-ELT will be able to probe the near-infrared as well as the optical. With a billion Euro sticker price, the E-ELT is sure to be one of the engineering feats of our time!

13.10.09:A Hawaiian Mega-scope?

The green light was given earlier this year in mid-July as to the site selection for a telescope that if built, will be the largest in the world. The Thirty Meter Telescope (TMT) will be parked atop Mauna Kea in Hawaii, home to a collection of scopes, including the Keck, Subaru, and Gemini instruments. As its name suggests, this telescope will sport a reflecting 30 meter mirror comprised of 492 hexagonal segments and operate in the near infrared as well as visible light. Its to be seen whether this will move the environmental lobby to protest as construction on Mauna Kea did in 2002. A point often missed in these debates is that the telescopes themselves need pristine dark skies to operate; this assures that over-development in the form of Costcos and subdivisions won’t visit the slopes of Mauna Kea anytime soon. A follow-up contender for the TMT is Mt. Cerro Armazones in the Atacama Desert in Chile, also dubbed the “most eligible mountain without an observatory.” The seeing is also a bit better in the Atacama, but of course that would mean the exodus of more American science (and dollars) overseas. The European Union is also eying Armazones for a possible site for its two main contenders: the Giant Magellan Telescope (GMT) at 24.5 meters, and the European Extremely Large Telescope (EELT) at a whooping 42 meters. Its sobering to think that these mega scopes may be the final say of large aperture on Earth; at a proposed 2 billion dollars to build the TMT, it becomes more cost effective to carry on further “aperture wars” in space!