Meteor Activity Outlook for March 7-13, 2009

March is the slowest month for meteor activity.
No major annual showers are active and only two very weak minor showers produce
activity this month. The sporadic rates continue a slow decline as seen from the
mid-northern latitudes and mid-southern rates reach a first half minimum. There
is not much to look forward to this month expect for the evening fireballs that
seem to peak this time of year from the northern hemisphere. This could be due
to the fact the antapex lies highest this time of year during the evening hours.

During this period the moon reaches its full
phase on Wednesday March 11th. At this time the moon lies 180 degrees opposite
the sun and is in the sky all night long. This weekend a small window of opportunity
exists between moonset and the start of morning twilight, when observers can view
under dark, moonless conditions. The estimated total hourly
rates for evening observers this week is near one as seen from the northern
hemisphere and two 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 six 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 during this
period due to lunar interference.

The radiant positions and rates listed below are exact
for Saturday night/Sunday morning March 8. 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 weak Delta Leonids (DLE) reached maximum on Wednesday February 25th.
The activity for this shower is nearly over and one would be lucky to see one
shower member per night at this time. The
radiant is now located at 11:56 (179) +12. This area of the sky lies in eastern
Leo, two degrees southeast of the second magnitude star Denebola (Beta Leonis).
This radiant is best placed near 0100 local standard time when it lies on the
meridian and is highest in the sky. With an entry velocity of 23 km/sec., the
average Delta Leonid meteor would be of slow speed.

The wide Antihelion (ANT) radiant is now centered at 12:00 (180) -01. This
area of the sky lies in western Virgo, five degrees west of the fourth magnitude
star Eta Virginis. This radiant is also best placed near 0100 LST. Due to the
large size of this radiant, any meteor radiating from southeastern Leo or western
Virgo could be a candidate for this shower. Rates at this time
should be near one per hour no matter your location. With an entry velocity of 30
km/sec., the average Antihelion meteor would be of medium-slow speed.

The Gamma Normids (GNO) are active from a radiant located at 15:32 (233)
-50. This area of the sky is located on the Lupus/Norma border, three degrees
northeast of the third magnitude star Zeta Lupi. With the maximum not occurring
until March 13th, current visual rates would still be less than one shower member
per hour, no matter your location. These meteors are best seen between 0400 and
0500 local standard time, when the radiant lies highest above the horizon. This
shower is best seen from the southern hemisphere, where the radiant lies high in
the sky at dawn. Meteors from this shower are not visible north of 40 degrees
north latitude and also poorly seen throughout most of the northern hemisphere.
An occasional shower member may be seen from the northern tropics, shooting upwards
from the southern horizon. At 56 km/sec. the Gamma Normids will usually produce
meteors of swift velocity.

As seen from the mid-northern hemisphere (45N) one would expect to see approximately
four 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 five 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. Sporadic
rates are reduced due to lunar interference.

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.