Viewing to Feature Io's Shadow on Jupiter

Jupiter’s fiery moon Io will cast its shadow onto Jupiter during a free, public viewing Friday, Oct. 15, with Westmont’s powerful Keck Telescope at the observatory near the soccer and baseball fields. People generally begin lining up for the first glimpse through the 24-inch reflector telescope after sunset, around 7 p.m. However, the shadow transit of Io will only be visible from 8:30-10:30 p.m.

Tom Whittemore, Westmont physics instructor, says the moon will dominate the southern sky since it will be gibbous (bulging outward) at nine-days old in the constellation Capricorn. “The spotlight will be on the wonderful crater triplet of Ptolemaeus, Alphonsus and Arzachel,” Whittemore says. “They will be near the terminator and should look dazzling.”

A variety of open clusters will also be observable in the northeastern sky with the rising winter Milky Way in Cassiopeia and Perseus.

Westmont serves as one of the public observing sites for the Santa Barbara Astronomical Unit (SBAU) every third Friday of the month. Members of the SBAU also bring their telescopes to the public viewing, which lasts for several hours. Free parking is available near the baseball field.