Meteor Activity Outlook for May 17-23, 2008

May is a fairly slow month for meteor activity.
The Eta Aquariids are very active the first week of the month then fade as the
month progresses. The only other showers active this month are the Eta Lyrids and
the Antihelion radiant. These will add only 2-3 meteors per hour to the total count.
Sporadic rates are low but steady as seen from the mid-northern hemisphere (45 N).
Sporadic rates seen from the mid-southern hemisphere (45 S) continue to rise this
month toward a maximum in July.

During this period the moon reaches its full phase
on Tuesday May 20. At this time the moon will be in the sky all night long. The
intense moonlight will obscure all but the brightest meteors making observations
difficult. The
estimated total hourly rates for evening observers this week is near one for those
located in the mid-northern hemisphere (45 N) and two for those viewing from the
mid-southern hemisphere (45 S). For morning observers the estimated total hourly
rates should be near five for those located in the mid-northern hemisphere (45 N)
and ten for those viewing from the mid-southern hemisphere (45 S). 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 and rates listed below are exact
for Saturday night/Sunday morning May 17/18. 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.