Meteor Activity Outlook for October 3-9, 2009

Meteor activity in general increases in October when compared to September. A major shower (the Orionids) is active most of the month along with several minor showers. Both branches of the Taurids become more active as the month progresses, providing slow, graceful meteors to the nighttime scene. The Orionids are the big story of the month reaching maximum activity on the 22nd. This display can be seen equally well from both hemispheres which definitely helps out observers located in the sporadic-poor southern hemisphere this time of year.

During this period the moon reaches its full phase on Sunday October 4th. At this time the moon lies in the sky all night long and severely hampers meteor observations. A small window of dark skies opens later in the week as the waning gibbous moon rises later in the evening allowing a couple of hours of dark sky between the end of evening twilight and moonrise. The estimated total hourly rates for evening observers this week is near three as seen from the northern hemisphere and two from the southern hemisphere. For morning observers the estimated total hourly rates should be near seven from the northern hemisphere and four as seen from the southern hemisphere. 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 severely reduced by bright moonlight.

The radiant positions and rates listed below are exact for Saturday night/Sunday morning October 3/4. 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 full descriptions of each active meteor shower will continue next week when the moon becomes less of a nuisance to observers.

The table below presents a condensed version of the expected activity this week. Rates and positions are exact for Saturday night/Sunday morning or the night of maximum activity for showers of short duration.