posted on Jul, 31 2009 @ 04:09 PM
Robert Lunsford-Meteorobs
Meteor activity kicks into high gear in August as seen from the northernhemisphere. The main reason for all this activity is the Perseid shower
thatpeaks on August 12. This shower is active most of the month and remainsabove the level of the sporadic background for a week centered on August
12.The sporadic activity is also increasing as seen from the northernhemisphere and is now nearly double the rates from just three months ago. Asseen
from south of the equator, meteor rates are still decent but fallingrapidly. The sporadic rates seen at the beginning of the month will be twiceas
much as those seen during the last days of the month. The Perseid radiantdoes not rise high into the sky as seen in the southern hemisphere so
ratesfrom this shower are greatly reduced when compared to the northernhemisphere. During this period the moon reaches its full phase on Thursday
August 6th.This weekend and early next week there is a window of opportunity to viewthe meteor activity during the dark period between moonset and
dawn. This isespecially true for observers viewing from the northern hemisphere as themoon currently lies well south of the ecliptic. As Wednesday
arrives the fullmoon is in the sky nearly the entire night. The estimated total hourly ratesfor evening observers this week is near four no matter
your location. Formorning observers the estimated total hourly rates should be near twentyseven for those located in the mid-northern hemisphere (45
N) and twentyfive for those viewing from the mid-southern hemisphere (45 S). Locationsbetween these two extremes would see activity between the listed
figures.These rates assume that you are watching from rural areas away from allsources of light pollution. The actual rates will also depend on
factorssuch as personal light and motion perception, local weather conditions,alertness and experience in watching meteor activity. Evening rates
arereduced due to moonlight. The radiant positions and rates listed below are exact for Saturdaynight/Sunday morning August 1/2. These positions do
not change greatly dayto day so the listed coordinates may be used during this entire period. Moststar atlases (available at science stores and
planetariums) will providemaps with grid lines of the celestial coordinates so that you may find outexactly where these positions are located in the
sky. A planisphere orcomputer planetarium program is also useful in showing the sky at any timeof night on any date of the year. Activity from each
radiant is best seenwhen it is positioned highest in the sky, either due north or south alongthe meridian, depending on your latitude. It must be
remembered that meteoractivity is rarely seen at the radiant position. Rather they shoot outwardsfrom the radiant so it is best to center your field
of view so that theradiant lies at the edge and not the center. Viewing there will allow you toeasily trace the path of each meteor back to the
radiant (if it is a showermember) or in another direction if it is a sporadic. Meteor activity is notseen from radiants that are located below the
horizon. The positions beloware listed in a west to east manner in order of right ascension (celestiallongitude). The positions listed first are
located further west thereforeare accessible earlier in the night while those listed further down the listrise later in the night.