Meteor Activity Outlook for March 31-April 6, 2012

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 25th, with a pronounced maximum on the 22nd. The Eta Aquariids start
appearing near the 28th 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 full phase on Friday April 6th. At that
time the moon will be located opposite the sun and will be in the sky all night
long. This weekend the waxing gibbous moon will set during the early morning
hours, allowing a few hours of dark skies for observing before the start of
morning twilight. This window of opportunity shrinks with each passing night
until late in the week when the moon is near full and in the sky all night long.
The estimated total hourly rates for evening observers this week is near two for
observers in the northern hemisphere and three for those south of the equator.
For morning observers the estimated total hourly rates should be near seven as
seen from mid-northern latitudes and twelve from mid-southern latitudes. 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. Evening rates are reduced during this period due to moonlight.

The radiant (the area of the sky where meteors appear
to shoot from) positions and rates listed below are exact for Saturday night/Sunday
morning March 31/April 1. 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 large Antihelion (ANT) radiant is currently located at 13:08 (204) -09. This
position lies in central Virgo, four degrees northwest of the first magnitude
star Spica (Alpha Virginis). Due to the large size of this radiant, Antihelion
activity may also appear from the nearby constellations of Corvus, extreme
eastern Hydra, southwestern Bootes, and northern Centaurus as well as Virgo.
This radiant is best placed near 0200 local daylight time (LDT), when it lies on
the meridian and is located highest in the sky. Rates at this time should be
near two per hour no matter your location. With an entry velocity of 30 km/sec.,
the average Antihelion meteor would be of slow velocity.

Studies of the IMO video database by Sirko Molau and Juergen Rendtel has
revealed a weak radiant active in the constellation of Cygnus this time of year.
The Zeta Cygnids (ZCY) are active from March 27 through April 13 with maximum
activity occurring on April 6. The current radiant position lies at 19:52 (298)
+39. This position lies in central Cygnus, six degrees west of the second
magnitude star Sadr (Gamma Cygni). The radiant is best placed during the last
dark hour before dawn, when it lies highest above the horizon in a dark sky. Due
to the northern declination of the radiant, this activity is not well seen from
the southern hemisphere. No matter your location, rates at this time are
expected to be less than one per hour. At 44km/sec. the Zeta Cygnids would
produce meteors of average velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see
approximately five sporadic meteors per hour during the last hour before dawn as
seen from rural observing sites. Evening rates would be near one per hour. As
seen from the mid-southern hemisphere (45S), morning rates would be near ten per
hour as seen from rural observing sites and two per hour during the evening
hours. Locations between these two extremes would see activity between the
listed figures. Evening rates are reduced during this period due to moonlight.

The table below presents a condensed version of the expected activity this week.
Rates and positions are exact for Saturday night/Sunday morning.