Vol. 38, No. 18

8-14-2007
By: Pam Frost Gorder

Telescope to push the limits

The clouds parted.

“It’s happening!” Bradley Peterson, chair of the Department of Astronomy, popped into the front of the bus just long enough to give a shout, then disappeared. “Everybody out!”

He strode across the gravel ledge, turned, and lifted his arms to form an “O.”

Gerald Newsom, professor emeritus, stepped in to the left, and clapped his hands above his head to form an “I.”

Astronomy faculty, staff and half a dozen alumni climbed out and looked above to the summit of Mount Graham at the International Observatory near Safford, Ariz. Just minutes before, the rainy season — what locals call the Arizona monsoon — had shrouded the peak in blue-gray mist. But now the sun broke through, and the astronomers seized the moment.

Two alums hurried over to join Peterson and Newsom in an “O-H.” The four squinted happily in the light as a phalanx of photographers formed and cheered them on: A human O-H-I-O in front of the Large Binocular Telescope.
It was a portrait 20 years in the making.

The telescope project began in the late 1980s. Since it is a telescope like no other, Ohio State and its four international partners have spent the years since gathering vast resources and inventing technologies to bring it to life. The university withdrew from the LBT partnership briefly in the early 1990s for financial reasons and rejoined in 1997. Since then, it has provided funds, instrumentation and expertise that will ultimately add up to a one-eighth share of the $120 million project.

When completed, the LBT will be the world’s largest telescope on a single mount, and offer 10 times the resolution of the Hubble Space Telescope.

This summer, with just about two years until it is fully operational, the LBT cut an impressive figure. The alumni event on Aug. 5 found both 8.4-meter mirrors locked aboard an eight-story superstructure that can only be described as part jungle gym, part space shuttle. Its also has the élan of a sportscar, since Italian partners painted it an incandescent Ferrari red.

“That’s scarlet,” Peterson corrected, to the alumni’s amusement.

And if the metallic silver insulation painted on the supports can be thought of as gray, then the LBT is indeed emblazoned in Buckeye colors.

But one of Ohio State’s real contributions to the project was visible in the shine of the mirrors. That came from research scientist Bruce Atwood and his instrumentation team, who developed the technology to coat the curved dishes with aluminum.

Then there’s the Multi-Object Double Spectrograph, or MODS — a set of two instruments that will capture the light reflected by the LBT mirrors, so that astronomers can analyze distant stars and galaxies. Richard Pogge, professor of astronomy, and his team are building MODS in the basement of McPherson Laboratory right now. The first spectrograph should be operational in mid-2008; the second, a year later.

Once both pieces are installed, they will be “the real workhorse instruments of the telescope,” said Richard Green, LBT director and the event’s tour guide.

Half a dozen other instruments will eventually join MODS and flip in and out of position on the superstructure like a giant Swiss army knife, depending on which tools astronomers want to use for a particular study. A second set of mirrors will change shape to tune out distortion caused by Earth’s atmosphere.

All that instrumentation will soon be in the hands of Ohio State students, a fact that Peterson says will help recruit the best aspiring astronomers to the university. The only drawback: They’ll have to journey to Tucson and take a two-hour drive up to the peak of Mount Graham, some 10,000 feet above sea level in the Coronado National Forest. The rocky road is known for destroying auto suspensions and is barely wide enough for two cars to pass each other coming and going. Twists and turns are punctuated with steep drop-offs — all with spectacular views of lush pine valleys.

Newsom and William Protheroe, a professor emeritus of astronomy who also attended the event, speculated that only one other telescope on Earth may be as difficult to reach: The MMT telescope on nearby Mount Hopkins, which has a peak of 8,500 feet.

Given the high-tech capability of LBT and the harsh environment, Ohio State astronomers are going to be doing extreme science on an extreme landscape.

That afternoon, the tour returned down the mountain to LBT base camp, which is hosted by telescope partner University of Arizona. As people got out to stretch their legs in the parking lot, the monsoon was still in full swing. Lightning bolts arced out of the purple sky to strike the mountaintops; rain could be seen far across the plains, where cacti and sage blooms dotted the horizon.

When he climbed back on the bus, Newsom was all smiles.

“Pretty dramatic, huh?”

Yeah, pretty dramatic.

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