Sky command

Clambering among girders and guy wires high in the air, Skidmore astronomy professor Mary Crone Odekon (at right) and Siena College’s Rose Finn explore
Puerto Rico’s Arecibo Observatory, home of the world’s largest radiotelescope. As
part of a National Science Foundation grant, Odekon and Scott Manglitz ’09 are one
of fourteen college teams to join Arecibo’s project to detect and map an estimated 25,000 galaxies as far away as 750 lightyears. The college teams visited in January for seminars, training, and a tour of the twenty-acre, thousand-foot-wide dish and the antennas and reflectors suspended 450 feet above it. Odekon says radiotelescopes, unlike optical ones, can detect vast clouds of cool gas that may be galaxies-in-waiting—they contain atomic hydrogen but have not yet formed stars. Radiotelescopes can also sense dark matter by its gravitational tug on hydrogen gas. Odekon and Manglitz plan to use data from Arecibo to “weigh” the atomic hydrogen and dark matter in groups of galaxies. —SR