Harvard To Help Build Magellan

Harvard will be among eight research institutions joining to build the largest telescope on the planet, the University announced Monday.

“This is one of the few scientific fields that has a significant element of romance,” said Charles A. Alcock, director of the Harvard-Smithsonian Center for Astrophysics, of the plan to build the Giant Magellan Telescope (GMT).

The increased power of the GMT’s mirrors will allow scientists to see further into space, gathering more information on extra-solar planet composition, the formation of galaxies, black holes and stars, as well as on newer astronomical topics like theories of dark energy.

“One of the amazing new things in science is that the expansion of the universe, which people have known about since 1929, has been speeding up, not slowing down due to gravity as everyone thought,” said Clowes Professor of Science Robert P. Kirshner ’70. “To figure out what this dark energy is, we need to go more precisely and further into the past.”

Figuring out what the dark energy means could call into question a number of the fundamental tenets of physics, Kirshner said.

Monday’s agreement will finance the development of the first of the GMT’s seven planned primary mirrors. The mirror is projected to cost between $16 and $17 million, of which the Center for Astrophysics will fund $3.5 million.

The entire GMT is estimated to cost half a billion dollars, and is scheduled for tentative completion in 2016.

Completion of the first mirror is important because five of the others will follow the same design, said Dan Fabricant, a Smithsonian scientist and a lecturer in astronomy at the Faculty of Arts and Sciences.

“We’re one of the leading institutions in astrophysics,” Alcock said. “If we want to keep that lead, maybe even extend it, it’s critical for us to participate.”

In addition to Harvard and the Smithsonian, the consortium includes Carnegie Observatories, the University of Arizona, the University of Michigan, the University of Texas at Austin, the Massachusetts Institute of Technology and Texas A&M.

“It’s a huge adventure,” Kirshner said. “There’s widespread support for doing something along these lines and the topic has strong popular appeal.”

The GMT is a segmented telescope, meaning that it contains several layers of mirrors. The seven primary mirrors, those responsible for collecting the light or photons—essentially the data—from outer space, will be 8.4 meters in diameter. This surpasses the diameter of existing Magellan telescopes by almost two meters and increases by almost five times the amount of light the telescope is capable of collecting.

The primary mirrors reflect the light onto secondary mirrors, which are responsible for correcting whatever blurring has occurred. In the current Magellan telescopes, the curvature of the mirrors must be adjusted almost once a minute. The GMT’s secondary mirrors, in contrast, may be able to correct for the “wiggles in the atmosphere” using an adaptive process which is more accurate.

“The GMT just covers a tremendous span of research,” Fabricant said, “There’s a whole host of scientific projects we anticipate, but science changes, so what we do in 10 years may be slightly different.”

The most likely location of the telescope is Las Campanas, Chile, where the Magellan telescopes are already located and the Carnegie Observatories have worked for 20 years. Chile’s high altitude and dry weather make it one of the better locations from which to observe outer space, Alcock said.