Meteor Activity Outlook for March 28-April 3, 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 first
quarter phase on Thursday April 2nd. At this time the moon lies ninety degrees
east of the sun and sets near 0100 local daylight time (LDT). This weekend the
waxing crescent moon will set during the evening hours allowing the more active
morning hours to remain free of interfering moonlight. The estimated total hourly
rates for evening observers this week is near three as seen from the northern
hemisphere and four for those situated south of the equator. For morning observers
the estimated total hourly rates should be near ten for those located in the
mid-northern hemisphere (45 N) and fourteen 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.

The radiant positions and rates listed below are exact
for Saturday night/Sunday morning March 28/29. 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 following showers are expected to be active this week:

The wide Antihelion (ANT) radiant is now centered at 13:24 (201) -09. This
area of the sky lies in central Virgo only two degrees north of the first magnitude
star Spica (Alpha Virginis). This radiant is also best placed near 0200 LDT. Due
to the large size of this radiant, any meteor radiating from eastern Corvus, western
Libra, or Virgo could be a candidate for this shower. Rates at this time should be
near two per hour no matter your location. With an entry velocity of 30km/sec.,
the average Antihelion meteor would be of medium-slow speed.

The video studies of Sirko Molau have revealed a weak radiant active in Cygnus
this time of year. The Zeta Cygnid (ZCY) radiant is currently located at
19:48 (297) +36. This area of the sky is located in western Cygnus, three degrees
northwest of the fourth magnitude star Eta Cygni. Maximum activity does not occur
until April 10 so current rates are expected to be well less than one per hour.
These meteors are best seen during the last dark hour before dawn, when the radiant
lies highest above the horizon in a dark sky. This shower is best seen from the
northern hemisphere, where the radiant lies high in the sky at dawn. At 41 km/sec.
the Zeta Cygnids will usually produce meteors of medium velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately
eight Sporadic meteors per hour during the last hour before dawn as seen
from rural observing sites. Evening rates would be near two per hour. As seen from
the mid-southern hemisphere (45S), morning rates would be near twelve per hour as
seen from rural observing sites and three per hour during the evening hours. Locations
between these two extremes would see activity between the listed figures.

The table below presents a summary of the expected activity this week. Rates and
positions are exact for Saturday night/Sunday morning but may be used all week.