Published: 2013-12-13 17:33:00
Updated: 2013-12-13 17:37:39
Posted December 13, 2013
By Tony Rice
The Geminid meteor shower peaks this weekend, but Friday night will probably be our only night to enjoy the show. Clouds are expected to move in early Saturday morning.
The Geminids are the last big meteor shower of the year. The rate of meteors observed has been as high as 150 meteors per hour. Many astronomers list it as their favorite not just because it tends to produce a higher number of visible meteors and the relatively slow speed the meteors travel across the sky, but also because their source is so weird.
Unlike August's Persieds, October's Orionids, or April's Lyrids, December's Geminids originate from dust and rock spewing from an asteroid rather than a comet. Asteroid 3200 Phaethon was discovered in 1983 by NASA's IRAS space telescope. Astronomers think that heating from the sun is causing it to break down, leaving a trail of rock and dust behind. As Earth passes through that trail, we are treated to meteors or "shooting stars."
However, this weekend's nearly full moon will make seeing dimmer meteors a challenge, reducing expectations to 40 - 60 meteors visible per hour. Here in North Carolina, clouds are expected to move in after midnight and further spoil our view. By the prime meteor viewing hours between 4am and dawn, mostly cloudy skies are expected.
Though conditions are less than ideal, it is still worth going outside to catch the cosmic display. Give yourself a few minutes to allow your eyes to adjust to the darkness, and you will see much more.
Bundle up, temperatures are expected to be in the high 30s around midnight, dipping close to freezing overnight. I find a steaming cup of hot chocolate enhances my ability to spot meteors as well, especially the Geminids.
Meteors will appear to radiate from above Castor and Pollux, the bright stars of the constellation Gemini, but may appear anywhere in the sky. The even brighter object to the right is Jupiter. A decent pair of binoculars will reveal Jupiter's moons Ganymede (above the planet), Io (just below) and Europa (further below).
Even with the clouds and the moon getting in the way of the show, you can still experience it online from the warmth of your home. The Slooh online observatory begins a free online viewing of the event from their website as well as their free iPhone/iPad app beginning at 5:30 pm EST from their all-sky camera in the Canary Islands off Africa. The webcast will be hosted by astronomer Bob Berman.
NASA will also have a live chat from 11 pm EST to 3 am EST with astronomer Bill Cooke answering questions. The webcast will include a feed of the all-sky camera over the Marshall Space Flight Center in Huntsville, Ala.
Tony Rice is a volunteer in the NASA/JPL Solar System Ambassador program and software engineer at Cisco Systems. You can follow him on twitter @rtphokie.