Meteor Activity Outlook for December 10-16, 2011

During this period the moon reaches its full phase on Saturday December 10th. At
this time the moon will lie above the horizon the entire night and will severely
impact meteor observing by obscuring all but the brightest meteors. As this week
progresses the moons phase will wane and it will rise approximately
forty-five minutes later each night. Toward the end of the week there will be a
window of opportunity to view evening activity under dark skies between the end
of dusk and moon rise. The estimated total hourly rates for evening observers
this week is near two as seen from the northern hemisphere and one as seen from
the southern hemisphere. For morning observers the estimated total hourly rates
should be near eight as seen from mid-northern latitudes and five from
mid-southern latitudes. The actual rates will also depend on factors such as
personal light and motion perception, local weather conditions, alertness and
experience in watching meteor activity. All rates are reduced due to intense
moonlight.

The radiant (the area of the sky where meteors appear to shoot from) positions
and rates listed below are exact for Saturday night/Sunday morning December
10/11 These positions do not change greatly day to day so the listed coordinates
may be used during this entire period. Most star atlases (available at science
stores and planetariums) will provide maps with grid lines of the celestial
coordinates so that you may find out exactly where these positions are located
in the sky. A planisphere or computer planetarium program is also useful in
showing the sky at any time of night on any date of the year. Activity from each
radiant is best seen when it is positioned highest in the sky, either due north
or south along the meridian, depending on your latitude. It must be remembered
that meteor activity is rarely seen at the radiant position. Rather they shoot
outwards from the radiant so it is best to center your field of view so that the
radiant lies at the edge and not the center. Viewing there will allow you to
easily trace the path of each meteor back to the radiant (if it is a shower
member) or in another direction if it is a sporadic. Meteor activity is not seen
from radiants that are located below the horizon. The positions below are listed
in a west to east manner in order of right ascension (celestial longitude). The
positions listed first are located further west therefore are accessible earlier
in the night while those listed further down the list rise later in the night.

The list below presents a condensed version of the expected activity this week.
Rates and positions are exact for Saturday night/Sunday morning. Detailed
descriptions of each shower will continue next week when the moonlight is less
of a problem.