South Pole centennial history includes UChicago telescopes

Roald Amundsen reached the South Pole on Dec. 14, 1911. The following year, Arctic explorer Admiral Robert Peary wondered about the scientific merits of making a continuous year of astronomical observations from the South Pole. So Peary sent a letter to Edwin Frost, director of the University of Chicago [1]’s Yerkes Observatory [2], asking about the idea.

Frost rejected the idea, but his UChicago successors thought differently. In 1986 they established the first in a series of telescopes at the South Pole to take advantage of its high elevation (9,301 feet), its clear, dry atmosphere, and its uninterrupted view of the same patch of sky. UChicago scientists have since become a scientific fixture of the South Pole, which now enters its second century of human activity.

UChicago deployed its first telescopes as part of the Cosmic Background Radiation Anisotropy Experiment (COBRA). The largest COBRA telescope, called Python, recorded measurements of the cosmic microwave background — the big bang’s afterglow — that were 10 to 100 times better than any other Earthbound site conducting such studies.

Then came Chicago’s South Pole Infrared Explorer (SPIREX), the only telescope in the world that had a continuous view of the crash of Comet Shoemaker-Levy 9 with Jupiter in July 1995.

The Degree Angular Scale Interferometer [3] (DASI), which began operating in 2000, soon recorded slight temperature fluctuations in the cosmic microwave background. DASI’s precise measurements enabled cosmologists to verify the theory that ordinary matter, of which humans, stars and galaxies are made, accounts for less than 5 percent of the universe’s total mass and energy.

DASI also made the first detection of the much fainter polarization in the cosmic microwave background, which made the cover of the Dec. 19, 2002 issue of Nature [4].

Succeeding DASI was the South Pole Telescope [5], which collected its first data in February 2007. SPT studies the mysterious phenomenon of dark energy, which makes the expansion of the universe accelerate.

The South Pole Telescope will be featured as a Science Bulletin [6] next summer in a high-definition, seven-minute documentary at the American Museum of Natural History [7] in New York City.