Jupiter and Mars will be the focus of this month’s free public viewing of the stars Friday, June 17, beginning about 8:30 p.m. and lasting several hours at the Westmont Observatory. Despite a near-full moon, Westmont’s Keck Telescope, a 24-inch F/8 Cassegrain reflecting instrument with Ritchey-Chretien optics, will zoom in on Jupiter, which will be about 40 degrees above the horizon.
“If the sky is clear, we should be able to glean some details on the face of this giant gas ball,” says Thomas Whittemore, Westmont physics instructor. “The four Galilean moons of Jupiter should be easily seen tonight. Maybe we will glimpse a couple more moons with Westmont’s 8-inch refractor telescope too.”
Mars, which is about a month past opposition when the viewing of the Red Planet is optimal, has been in retrograde motion, moving from left to right in the sky in Libra. “This places Mars a bit higher in the sky at viewing time than it was last month,” Whittemore says. “But it’s still quite low and susceptible to atmospheric turbulence. This will affect the details we might normally be able to discern through Westmont’s refractor.”
Whittemore will turn a telescope toward some stellar objects away from the near-full moon. “Among these are the beautiful double star, Regulus, the easily-split pair in Leo, and two wonderful globular clusters, Messier 13 and Messier 3,” he says. “These balls of stars will be nicely positioned during the public outreach.”
The Keck Telescope, one of the most powerful on California’s Central Coast, is available to the public every third Friday of the month at the observatory in conjunction with the Santa Barbara Astronomical Unit, whose members bring their own telescopes to the college for the public to gaze through.