The 2003 Leonid Meteor Shower

http://science.nasa.gov/headlines/y2...bleleonids.htm

The 2003 Leonid Meteor Shower
NASA Science News
October 10, 2003

An unusual double Leonid meteor shower is going to peak next
onth over parts of Asia and North America.

The Leonid meteor shower is coming. Twice.

Bill Cooke of the Space Environments Group at the NASA Marshall Space
Flight Center explains: "Normally there's just one Leonid meteor shower
each year, but this year we're going to have two: one on Nov. 13th and
another on Nov. 19th."

Both are caused by comet Tempel-Tuttle, which swings through the inner
solar system every 33 years. With each visit the comet leaves behind a
trail of dusty debris--the stuff of meteor showers. Lots of the comet's
old dusty trails litter the mid-November part of Earth's orbit.

"Our planet glides through the debris zone every
year," says Cooke. "It's like a minefield.
Sometimes we hit a dust trail, sometimes we don't."
Direct hits can spark a meteor storm, which is
defined as more than 1000 shooting stars per hour.
"That's what happened in, for example, 1966 and
2001," says Cooke. "Those were great years for
Leonids."

"This year we're going to brush past two of the trails--no direct hits,"
he says. Even so, "we might have a nice display."

The first shower is expected on Nov. 13th around 17:17 UT. For about
three hours centered on that time Earth will be close to some dust shed
by Tempel-Tuttle in the year 1499. Sky watchers in Alaska, Hawaii and
along the Pacific rim of Asia are favored. They'll see anywhere from a
few to 40 meteors per hour--"if they can avoid the glare from that
night's gibbous Moon," cautions Cooke. A good strategy for moonlit meteor
observing: travel to high altitudes where the air is clear or stand in
the shade of a tall building or hillside.

Leonid meteor rates for selected cities: Nov. 13-14, 2003

City Local Time Maximum number of
Leonids in 15 min.

Los Angeles, CA 5:15 a.m. (Nov. 3
13th)

Seattle, WA 5:45 a.m. (Nov. 3
13th)

Fairbanks, AK 7:00 a.m. (Nov. 10
13th)

Honolulu, HI 5:30 a.m. (Nov. 9
13th)

Tahiti 5:00 a.m. (Nov. 6
13th)

Tokyo, Japan 2:30 a.m. (Nov. 18
14th)
Christchurch, New 3:30 a.m. (Nov.
Zealand 14th) 1

Sydney, Australia 3:30 a.m. (Nov. 9
14th)

Hong Kong 2:00 a.m. (Nov. 8
14th)

Beijing, China 1:45 a.m. (Nov. 10
14th)
Manila, the 1:45 a.m. (Nov.
Philippines 14th) 9

Table notes: Values listed in the 3rd column are the maximum number of
meteors an observer with perfectly clear dark skies might see in a
15-min. interval.

Curiously the Moon will be much closer to the 1499 trail than Earth will
be. "If the Moon had an atmosphere to catch the comet dust, there would
be about 1400 meteors per hour in lunar skies--a real storm," notes
Cooke. Instead, the Leonids will simply hit the ground.

Most Leonid meteoroids are microscopic, and when they hit the Moon they
do little more than raise a puff of moon dust. But a few will be bigger:
the size of golf balls or grapefruits. Traveling about 160,000 mph, these
impactors can cause explosions visible from Earth. (For more information
about this, read the Science@NASA story Explosions on the Moon.)

"This year we won't be able to see any lunar impacts," notes Cooke,
"because most of the Leonids will strike the far side of the Moon. Some
will hit the Earth-facing side, but the ground where they hit will be
sunlit. That makes it very hard to see the explosions."

The second and more impressive shower arrives almost a week later on Nov.
19th when Earth approaches a trail shed in 1533. "Sky watchers up and
down the US east coast will have the best view," says Cooke. "For a while
around 07:28 UT (2:28 a.m. EST), they could see more than one meteor per
minute." The Moon, a thin crescent on Nov. 19th, won't be bright enough
to interfere with the display. (Nor will it be close to the cometary dust
stream, so once again there will be no visible lunar explosions.)

Leonid meteor rates for selected cities: Nov. 19, 2003

City Local Time Maximum number of
Leonids in 15 min.

New York, NY 2:30 a.m. (Nov. 17
19th)

Miami, FL 2:30 a.m. (Nov. 14
19th)

Chicago, IL 1:30 a.m. (Nov. 13
19th)

Dallas, TX 1:45 a.m. (Nov. 9
19th)

Denver, CO 0:45 a.m. (Nov. 7
19th)

Los Angeles, CA 0:00 a.m. (Nov. 3
19th)

Caracas, Venezuela 3:30 a.m. (Nov. 17
19th)
San Juan, Puerto 3:30 a.m. (Nov.
Rico 19th) 18

Bermuda 3:30 a.m. (Nov. 19
19th)

London, England 5:45 a.m. (Nov. 7
19th)

Paris, France 6:30 a.m. (Nov. 6
19th)

Cooke assembled these forecasts using data from several researchers who
have done a good job predicting Leonid storms in recent years: Peter
Jenniskens at NASA's Ames Research Center, Jeremy Vaubaillon of the
Institut de Mecanique Celeste et de Calcul des Ephemerides in France, and
Esko Lyytinen. They mostly agree that Earth will encounter dust streams
on Nov. 13th and 19th, but there is less consensus about how intense the
resulting showers will be. Lyytinen, for instance, predicts a maximum of
just 30 meteors per hour on Nov. 19th. Vaubaillon says 100.

Who's right? See for yourself. Be outside when the time comes, looking
up.

"Ron Baalke" wrote in message ...
http://science.nasa.gov/headlines/y2...bleleonids.htm

The 2003 Leonid Meteor Shower
NASA Science News
October 10, 2003

An unusual double Leonid meteor shower is going to peak next
onth over parts of Asia and North America.

The Leonid meteor shower is coming. Twice.

Bill Cooke of the Space Environments Group at the NASA Marshall Space
Flight Center explains: "Normally there's just one Leonid meteor shower
each year, but this year we're going to have two: one on Nov. 13th and
another on Nov. 19th."

Both are caused by comet Tempel-Tuttle, which swings through the inner
solar system every 33 years. With each visit the comet leaves behind a
trail of dusty debris--the stuff of meteor showers. Lots of the comet's
old dusty trails litter the mid-November part of Earth's orbit.

"Our planet glides through the debris zone every
year," says Cooke. "It's like a minefield.
Sometimes we hit a dust trail, sometimes we don't."
Direct hits can spark a meteor storm, which is
defined as more than 1000 shooting stars per hour.
"That's what happened in, for example, 1966 and
2001," says Cooke. "Those were great years for
Leonids."

2001, while a nice show, was nothing like what happened
in 1966.

By now it's obvious these "researchers" have no clue about
the true location of the Tempel-Tuttle debris trail(s). They've
been all but promising a storm similar to 1966 every year
since 1999, and all of them have basically sucked (except
for 2001, and even that was a shower -- not a storm).

Rick

In message , Rick
writes

By now it's obvious these "researchers" have no clue about
the true location of the Tempel-Tuttle debris trail(s). They've
been all but promising a storm similar to 1966 every year
since 1999, and all of them have basically sucked (except
for 2001, and even that was a shower -- not a storm).

Were you clouded out last year? I was seeing better than one a second
despite a full moon, and the peak came exactly when it was predicted.
Next time that happens, phone me!
--
"It is written in mathematical language"
Remove spam and invalid from address to reply.

On Sat, 11 Oct 2003 01:16:26 -0700, "Rick" wrote:

2001, while a nice show, was nothing like what happened
in 1966.

By now it's obvious these "researchers" have no clue about
the true location of the Tempel-Tuttle debris trail(s). They've
been all but promising a storm similar to 1966 every year
since 1999, and all of them have basically sucked (except
for 2001, and even that was a shower -- not a storm).

Well, in 2001 I certainly saw a storm- close to 45 minutes with peaks of three
to five meteors per second. And I saw evidence that the same thing was happening
in 2002, but largely obscured by the Moon.

In fact, the predictions the last few years have been extremely accurate, and
only seem to be getting better as the debris trail theory improves, and
particularly as the models for Tempel-Tuttle debris are refined.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

Rick wrote:
2001, while a nice show, was nothing like what happened
in 1966.

By now it's obvious these "researchers" have no clue about
the true location of the Tempel-Tuttle debris trail(s). They've
been all but promising a storm similar to 1966 every year
since 1999, and all of them have basically sucked (except
for 2001, and even that was a shower -- not a storm).

I'd say that the current dust trail models are remarkably accurate,
especially in the timing. Jane and I flew on the 2002 mission to
document the two storm peaks. The peaks were within 15 minutes of the
forecast time. That continues to amaze me.

Certainly the rate forecasts are not as accurate as the timing, but I
personally documented rates over 1,000/hour in Alice Springs, Australia,
during the second peak of the 2001 storm.

I agree that it's difficult to model how much material is in each of
the dust trails, which is why we continue to document and study the
Leonids.

But to say they have "no clue" is absurd.

Mojo
2002 Leonid MAC scrapbook: http://www.whiteoaks.com/mac-2002/
--
Morris Jones *
San Rafael, CA

http://www.whiteoaks.com

I don't know if part of this is the fault of the press, but I bet most of it
is. The plain fact of the matter is that these meteor streams in space are
not continuous or evenly spread along their path. Clumps of material occur,
and in fact have to occur given the origin of the material and to a lesser
extend the gravitational effects of the planets. But in the Grand Tradition
of glossing over the details nd painting the picture in overly-broad
strokes, the media gives the impression that the sky will fill with stars.
This happened with the Leonids a couple of times, but the effect, if memory
serves, was fairly localized and the duration short. So the distortion
caused by the press, and perhaps by wishful thinking and hoping, hypes the
event and raises expectations to unrealistic levels.
--
----------------------------------------------------------------------
Pinprick holes in a colorless sky
Let inspired figures of light pass by
The Mighty Light of ten thousand suns
Challenges infinity, and is soon gone




"Morris Jones" wrote in message
...
Rick wrote:
2001, while a nice show, was nothing like what happened
in 1966.

By now it's obvious these "researchers" have no clue about
the true location of the Tempel-Tuttle debris trail(s). They've
been all but promising a storm similar to 1966 every year
since 1999, and all of them have basically sucked (except
for 2001, and even that was a shower -- not a storm).

I'd say that the current dust trail models are remarkably accurate,
especially in the timing. Jane and I flew on the 2002 mission to
document the two storm peaks. The peaks were within 15 minutes of the
forecast time. That continues to amaze me.

Certainly the rate forecasts are not as accurate as the timing, but I
personally documented rates over 1,000/hour in Alice Springs, Australia,
during the second peak of the 2001 storm.

I agree that it's difficult to model how much material is in each of
the dust trails, which is why we continue to document and study the
Leonids.

But to say they have "no clue" is absurd.

Mojo
2002 Leonid MAC scrapbook: http://www.whiteoaks.com/mac-2002/
--
Morris Jones *
San Rafael, CA

http://www.whiteoaks.com

On Sat, 11 Oct 2003 18:22:21 GMT, "David Nakamoto" wrote:

I don't know if part of this is the fault of the press, but I bet most of it
is. The plain fact of the matter is that these meteor streams in space are
not continuous or evenly spread along their path. Clumps of material occur,
and in fact have to occur given the origin of the material and to a lesser
extend the gravitational effects of the planets. But in the Grand Tradition
of glossing over the details nd painting the picture in overly-broad
strokes, the media gives the impression that the sky will fill with stars.
This happened with the Leonids a couple of times, but the effect, if memory
serves, was fairly localized and the duration short. So the distortion
caused by the press, and perhaps by wishful thinking and hoping, hypes the
event and raises expectations to unrealistic levels.

Indeed. And this also describes the situation in 1966, where the vast majority
of people saw only a good Leonid year, not the storm of a lifetime. My
conditions in 2001 were better than in 1966.

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

"Rick" wrote in message ...


2001, while a nice show, was nothing like what happened
in 1966.

By now it's obvious these "researchers" have no clue about
the true location of the Tempel-Tuttle debris trail(s). They've
been all but promising a storm similar to 1966 every year
since 1999, and all of them have basically sucked (except
for 2001, and even that was a shower -- not a storm).

It may have not been quite up to the 1966 storm, but there were a
number of places on Earth where the activity reached storm level (you
apparently weren't at the right place at the right time). Even last
year (2002) when the nearly-full moon was up, there was a brief time
when the number of meteors seen in the middle of the U.S. reached
near-storm levels (I saw 5 appear in less than one second at one
point, although the hourly rate was still in the several hundred per
hour range). Even out of the peaks, the 1999 display was better than
any other annual shower I have ever seen (well over 300 meteors
visible per hour for at least two hours). The 2000 shower had moon
problems, but still ranked well above the shower rates for every
single annual shower. (I was clouded out but had over 500 radio
meteor "pings" per hour). The 2001 shower was also vastly better than
any other annual shower I have ever seen (not quite a storm, but
pretty close for a while, as they were up to 19 meteors in a one
minute interval), so I would not say that any of them "basically
sucked". Quite frankly, the Leonids from 1999 to 2002 were the best
showers I will probably ever see. It looks like you got your hopes up
a little too high, as nobody "promised" a storm, but indicated that
one was possible (and to some extent, they were right). Clear skies
to you.

David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 11th Annual NEBRASKA STAR PARTY *
* July 18-23, 2004, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************

"David Knisely" wrote in message
m...
"Rick" wrote in message
...


2001, while a nice show, was nothing like what happened
in 1966.

By now it's obvious these "researchers" have no clue about
the true location of the Tempel-Tuttle debris trail(s). They've
been all but promising a storm similar to 1966 every year
since 1999, and all of them have basically sucked (except
for 2001, and even that was a shower -- not a storm).

It may have not been quite up to the 1966 storm, but there were a
number of places on Earth where the activity reached storm level (you
apparently weren't at the right place at the right time). Even last
year (2002) when the nearly-full moon was up, there was a brief time
when the number of meteors seen in the middle of the U.S. reached
near-storm levels (I saw 5 appear in less than one second at one
point, although the hourly rate was still in the several hundred per
hour range). Even out of the peaks, the 1999 display was better than
any other annual shower I have ever seen (well over 300 meteors
visible per hour for at least two hours). The 2000 shower had moon
problems, but still ranked well above the shower rates for every
single annual shower. (I was clouded out but had over 500 radio
meteor "pings" per hour). The 2001 shower was also vastly better than
any other annual shower I have ever seen (not quite a storm, but
pretty close for a while, as they were up to 19 meteors in a one
minute interval), so I would not say that any of them "basically
sucked". Quite frankly, the Leonids from 1999 to 2002 were the best
showers I will probably ever see. It looks like you got your hopes up
a little too high, as nobody "promised" a storm, but indicated that
one was possible (and to some extent, they were right). Clear skies
to you.

David W. Knisely
Prairie Astronomy Club: http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

This is why I'd rather try and catch a comet or some other solar system
event. Well, not transits of Mercury and Venus across the Sun; it can't
compare with the Moon doing it and revealing the Corona. But the fickleness
of meteor showers, and their dependency on where you are and when you
observe, not to mention the uneven distribution of material in the stream,
even if you know precisely where it is and where it will hit the Earth,
leave me cold. At least comets don't vary their appearance much hour to
hour.
^_^