Meteor Activity Outlook for April 11-17, 2009

Meteor activity picks up a bit during April as
two major showers are active during the month. The first of these, the Lyrids,
are active from the 16th through the 27th, with a pronounced maximum on the 22nd
and 23rd. The Eta Aquariids start appearing near the 27th and reach maximum activity
during the first week in May. 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) rise this month toward a maximum in July.

During this period the moon reaches its last
quarter phase on Friday April 17th. At this time the moon lies ninety degrees
west of the sun and rises near 0100 local daylight time (LDT) The moon remains
above the horizon the remainder of the night. This weekend the waning gibbous
moon will rise during the early evening hours, spoiling the view the remainder
of the night. The estimated total hourly rates for evening observers this week
is near two as seen from the northern hemisphere and three for those situated
south of the equator. For morning observers the estimated total hourly rates
should be near five for those located in the mid-northern hemisphere (45 N) and
seven for those viewing from the mid-southern hemisphere (45 S). Locations
between these two extremes would see activity between the listed figures. 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. Meteor rates are reduced this week due to the
bright moonlight.

The radiant positions and rates listed below are exact
for Saturday night/Sunday morning April 11/12. 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.