Explorit: Nights of the comets

By Vinita Domier

Everyone is invited to Saturday’s meeting of the Davis Astronomy Club at Explorit, 3141 Fifth St. in Davis, starting at 7 p.m. You do not have to pay any dues to be a member of the Davis Astronomy Club. All ages are welcome to attend the featured presentation indoors, followed by the star party outdoors (weather permitting).

This month, we will discuss comets, as there is a rare sighting of a comet in the night sky in March. The first of two very bright comets to be visible from the Earth made its closest approach to Earth on March 5, and is now becoming visible in the Northern Hemisphere. Comets, along with asteroids, are non-planetary solar system objects that are made up of ice, rocks and minerals.

These icy bodies develop beautiful tails when in close vicinity of the sun, due to the evaporation of gases and dust in their nuclei. Few comets can be seen with the naked eye when they are close to the sun, and most are visible only with binoculars or telescopes.

Comet C/2011 L4 Pan-STARRS was closest to the Earth on March 5 and is visible in the western sky after sunset with an estimated magnitude of +2 or +3. On Saturday, it passed closest to the sun and developed a long tail. Best viewing is this week, when the comet is visible near a thin crescent moon.

It will move northward each evening during March as it moves from being in front of the constellation Pisces to being in front of the constellations Pegasus and Andromeda. By the end of the March, the comet will be visible in the eastern sky just before sunrise, but will be fainter in magnitude.

Comet Pan-STARRS may just be the warm-up act for a potentially even more impressive comet due to arrive in November. If it is not destroyed by the sun during its closest approach on Nov. 28, Comet ISON has the potential to be as bright as a full moon, possibly even visible in daylight.

Comet ISON, discovered last year by two amateur astronomers in Russia, is expected to pass as close as 800,000 miles from the surface of the sun — significantly closer than the 27 million miles that Comet Pan-STARRS passed during its closest approach last Saturday.

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Explorit’s coming events:

* Summer Camp Volunteer Recruitment: Explorit seeks volunteers from now through May 10 to assist with activities during Summer Camp 2013. Volunteers must be at least 12 years old. If you are interested in volunteering please email Lisa at lisaj@explorit.org for more information and a volunteer application.

* Explorit will be open for spring break: March 25 to April 7 from 1 to 5 p.m. with the debut of  the “Beautiful World: Science and Art” exhibition.

— Explorit Science Center is at 3141 Fifth St. For more information, call 530-756-0191 or visit www.explorit.org, “like” Explorit on Facebook at www.facebook.com/explorit.fb or follow on Twitter at @ExploritScience