Meteor Activity Outlook for July 19-25, 2008

After several months of low activity the meteor
rates for both hemispheres see a marked increase in July. In the northern hemisphere
the change is not noticeable until mid-month when several southern radiants, the
Perseids, and sporadic rates all increase in activity. Southern rates are good all month long.

During this period the moon reaches its last quarter
phase on Friday July 25. At this time the moon will rise near 0100 local daylight
time (LDT) and will be in the sky the remainder of the morning. This weekend and
early next week 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 two for those located in the mid-northern hemisphere (45 N) and
three for those viewing from the mid-southern hemisphere (45 S). For morning observers
the estimated total hourly rates should be near ten for those located in the
mid-northern hemisphere (45 N) and fifteen 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 July 19/20. 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.