EDITORS and NEWS/PUBLIC AFFAIRS
DIRECTORS: Press releases
can be downloaded at www.fresnostatenews.com. University Relations also provides releases for news media companies
via e-mail. To be added to the
distribution list, send your e-mail address to tomu[at]csufresno.edu.
FOR IMMEDIATE RELEASE Contact: Tom Uribes
Nov. 12, 2001 (559) 278-2795
NOTE: Dr. Ringwald will be available for media this week most
of Tuesday and Thursday and 1 to 3 p.m. the remaining days. For an appointment,
contact Tom Uribes in University Relations.
PHYSICS PROF OFFERS VIEWING TIPS ON
LEONID METEORS DUE NOV. 17 AND 18
The most spectacular meteor show since 1966 — the Leonid Meteor Shower — is expected to light up the sky this weekend, Nov. 17 and 18, and a California State University, Fresno physics professor offers some tips on the best time and place to observe the phenomena.
“City light absolutely kills meteors,” said Dr. Frederick Ringwald. “One must be in a dark country sky to see them. The time to see them is between midnight and dawn, as the Earth moves into the meteor stream — not in the early evening, when most people want to observe.”
He said most forecasts predict there will be a peak on Nov. 18 at 2 a.m.
The November shower comes from the constellation Leo, hence its name, Ringwald said, explaining that meteor showers occur when the Earth moves through a stream of debris left over by a comet.
A good meteor shower, such as the Perseids in August, is typically 60 meteors per hour, he said. But predictions for the Leonid shower are for a Zenithal Hourly Rate (ZHR) between 2,000 to 30,000 meteors per hour, according to the November issue of Sky & Telescope.
“If this prediction is correct---and I make NO guarantees---we are in for a treat.” Ringwald said. “This is also a perfect time to observe them, as Earth is moving into the stream in the morning.”
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Ringwald said Peter Jenniskens of the SETI Institute also has predicted peak activity at 10:00 UT on Nov. 18, producing between 4,000 to 30,000 meteors per hour, plus a second peak about eight hours later.
“All other models predict that the second peak will be the dominant one,” Ringwald said. “But, if the Jenniskens model is correct, the western United States would be among the best places on Earth to observe this rare and spectacular event.”
Ringwald saw the 1998 Leonids from Florida.
“At a ZHR of 900 meteors per hour, it was like a good 4th of July show, although it didn't look like the end of the world,“ he recalled. “I saw hundreds of meteors out of the corner of my eye, as I was riding a bicycle to the beach, where my friends were. A ZHR of two to three times that would be quite amazing.”
But he also warns that viewers could possibly be left completely in the dark.
“Comets are notoriously fickle,” Ringwald said, emphasizing that he is not guaranteeing meteors may be seen at all, especially if people expect to see them from their backyard, within the city, before midnight.
"They will see exactly nothing, and, after they saw me in the news telling them what to expect, I will get blamed for it!”
Ringwald's recommendations on the best way to observe meteors out in the lightless countryside and what to bring: “to observe meteors, bring a comfy, reclining, lawn or lounge chair, for you to sit in as you look up at the sky. Also be sure to bring heavy clothing, to keep you warm — it will be November, after all. A thermos or two of something warm and caffeine-laden would also be useful.”
For technical background provided by Ringwald on the Leonid Meteor Shower, log on to www.fresnostatenews.com.
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Technical background for the Leonid Meteor Shower
(Provided by Dr. Frederick Ringwald, Fresno
State physics professor)
Almanac for 2001 November 18-19 for Fresno, California (from John
Thorstensen's excellent program skycalc):
long. 7 58 53 (h.m.s) W,
lat. 36 46.8 (d.m), elev. 105 m Pacific Daylight Savings Time assumed from 2 AM
on 2001 Apr 1 to 2 AM on 2001 Oct 28; standard zone = 8 hrs W
For the night of: Sun, 2001
Nov 18 ---> Mon, 2001 Nov 19 Local midnight = 2001 Nov 19, 8 hr UT, or JD
2452232.833 Local Mean Sidereal Time at midnight = 3 54 48.6
Sunset ( 0 m horizon): 16 48
PST; Sunrise: 6 41 PST Evening twilight: 18 18 PST; LMST at evening twilight:
22 11 Morning twilight: 5 11 PST; LMST at morning twilight: 9 07 12-degr
twilight: 17 47 PST --> 5 42 PST; night center: 23 44 PST
Moonset : 19 51 PST
Moon at civil midnight:
illuminated fraction 0.172 3.6 days before first quarter, RA and dec: 19 10 40,
-24 25.0
The sun is down for 13.9 hr;
10.9 hr from eve->morn 18 deg twilight.
9.3 dark hours after moonset
and before beginning of twilight.