Here is another reason to wake up early on Saturday morning - a rare
meteor shower! Bright shooting stars should be visible even with a
big old bright moon, and our city light pollution. Look to the East
and Northeast.
"Some time in the 40 years or so around 4 A.D., comet Kiess (C/1911
N1) passed by the Sun, ejecting a cloud of dust particles. The comet
returned in 1911, after completing one orbit. The dust particles were
pushed by the Sun's light into slightly wider orbits and have been
returning ever since, forming a thin ongoing stream of dust that
usually passes just outside Earth's orbit. On occasion, the combined
gravity of the solar system's planets moves this dust trail into
Earth's path. Earth encountered this 2000-year-old dust in 1935,
1986, and 1994, causing a meteor shower known as the Aurigids."
http://aurigids.seti.org/
Best viewing direction:
Best viewing: Keep Moon out of field of view (best to block behind
obstruction such as telephone pole, then watch whole sky), avoid city
haze that scatters moonlight
Best direction: East and Northeast
Best time: Start one hour before peak, then see the rate of meteors
increase and decrease while Earth travels through the shower
When:
Date: 2007 September 1
Peak time: about 11:33 +/- 20 minutes UT (= 04:33 a.m. Pacific
Daylight Savings Time).
Duration: about 1.5-hour
Width: 25 minutes above half the peak rate
What:
Peak rate: ZHR (Zenithal Hourly Rate) = 200 per hour (10-minute interval)
Meteor brightness: mostly -3 to +3 magnitude
Shower radiant: constellation Auriga (Radiant at RA = 92, Decl. = +39)
Entry speed: Vinf = 67 km/s
Where:
Visible from: California, Oregon, Hawaii, Alaska, Mexico [see flux
applet for visibility from your location]
Moon:
4 days past Full Moon, high in the sky
Important because:
Once in a lifetime crossing of the dust trail of a known long period
comet (comet Kiess).
Public interest:
When you make a wish, consider that each meteoroid was released at
some unknown moment during the period 36 B.C. - A.D. 45.
Links: NASA Ames News Release:
http://www.nasa.gov/centers/ames/news/releases/2007/07_59AR.html
--
Jane Houston Jones
Senior Outreach Specialist, Cassini Program
JPL - 4800 Oak Grove Drive, MS 230-205
Pasadena, CA 91109 818-393-6435
jane.h.jones(a)jpl.nasa.gov
Cassini SOC
http://soc.jpl.nasa.gov/index.cfm
What's Up?
http://education.jpl.nasa.gov/amateurastronomy/index.html