Meteor Activity Outlook for May 4-10, 2007

May provides the peak of the Eta Aquarid meteor
shower. This is the strongest shower visible from the southern hemisphere but
unfortunately this year glare from the waning gibbous moon will obscure all but
the brightest meteors. The much weaker Eta Lyrids peak on May 9 under slightly
better conditions. Sporadic rates seen in the northern hemisphere are nearing the
nadir of their activity curve. The lowest rates are observed in June. On a positive
note, rates seen from the southern hemisphere are increasing toward a July maximum.

During this period the moon reaches its last
quarter phase on Thursday May 10. The waning gibbous moon will be a major factor
in trying to observe this week. The sources of meteors listed below are active
during this period but will be difficult to observe this week due to the lunar
glare. If your sky is transparent and the limiting magnitude exceeds +5.0, then
you may be able to achieve some success.
The estimated total hourly rates for evening observers this week is near one for
those in the Northern Hemisphere and two for those located in the Southern Hemisphere.
For morning observers the estimated total hourly rates should be near eight for
those viewing in the Northern Hemisphere and twelve for those in the Southern
Hemisphere. These rates assume that you are watching from rural areas away from
all sources of light pollution. 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. Rates are reduced this week due to intense
moonlight.

The radiant positions listed below are exact for Saturday
night/Sunday morning May 5/6. 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. Doing this 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.