The 2002 Leonid meteor shower promises a remarkable show in the early morning hours of Nov. 19, and SPACE.com has obtained the latest forecasts and city-by-city charts predicting activity around the world.

Though a nearly full Moon will outshine fainter meteors, skywatchers should not be discouraged, experts say. A storm of shooting stars, along with possible bright fireballs, is in store during a display that wont be repeated for at least three decades.

• Forecast & U.S./World City Charts
• About the Rates
• About the Charts
• What is the Radiant?
• This Years Pesky Moon
• What Causes the Leonids?

Peak activity will come between midnight and sunrise on Tuesday, Nov. 19. Astronomers predict two outbursts one for Europe and another for North America and parts of northern South America. Most viewers outside these locations will see only a trickle of shooting stars, though more than on other nights during the year.

"It should be a good show, even with the Moon," says Bill Cooke, a meteor expert at NASAs Marshall Space Flight Center.

Predicted peak times vary by longitude (your east-west location). Be warned: Meteor forecasting is a young discipline, and times may vary from the forecasts. Its wise to go out 1-2 hours before your predicted peak, and stay at least that long afterward or until it is daylight. The hours from midnight to dawn are best regardless of where you live, though a handful of meteors will be visible before midnight.

Avid observers should also plan to get out on the mornings of Nov. 17 and 18, when rates will be picking up. This offers a good chance to practice and to scope a good location; this year, youll want a tall obstruction a tree, building or mountain to block the Moon, which will be in the west.

An early morning outburst is expected to generate a sharp peak of activity at around 5:30 a.m. ET (2:30 a.m. PT) on Nov. 19.

"I estimate folks in the U.S. should see about one Leonid every 6-10 seconds near the time of the peak," Cooke said, having taken into account the effect of the Moon. Residents of Canada and Mexico will see this outburst, too.

Viewers with heavy local light pollution from cities or strong backyard lighting will see lower rates.

Eastern residents will get the best view as the outburst comes just before dawn there, when the Leonid radiant is high in the sky and the Moon is low in the west. Expect up to 10 shooting stars per minute during the peak, an hourly rate of 600. Seasoned meteor watchers with optimal conditions might see rates briefly climb as high as 2,000 per hour.

For people in the west and in the middle of the continent, the peak comes when the Moon is higher and the radiant is lower. Experts say casual skywatchers should not make too much of this the show will still be great, and its probably not worth the cost of a plane ticket. Expect 6 or more shooting stars per minute at the peak, an hourly rate of 360. Again, experienced skywatchers in good conditions might see higher rates.

Europeans should see hourly rates between 500 and 1,000, or about 8 to 16 per minute, during an outburst around 0400 UT. Viewers with heavy local light pollution from cities or strong backyard lighting will see lower rates.

"North Africa should experience roughly the same rates as European cities at the same longitude," Cooke said.

Observers in Asia will see no more than a few dozen bright meteors per hour near the times of the predicted outbursts (0400 UT and 1030 UT on Nov. 19). The totals could be less.

People in Australia, South Africa and southern South America will see no more than a few dozen bright meteors per hour at the times surrounding the peaks (0400 UT and 1030 UT on Nov. 19). While not a significant shower, this is still more than one can see on other nights.

"The northern part of South America may see as many as 400 Leonids per hour near the peak," Cooke said.

Official meteor forecasts are based on 15-minute intervals. They are often expressed as hourly rates. In reality, peak rates never hold for an entire hour.

A meteor shower qualifies as a "storm" when its hourly rate exceeds 1,000 for a 15-minute period. Expressed another way, a forecasted hourly rate of 1,000 means 1,000 shooting stars per hour for a period of at least 15 minutes. That equates to a little more than 16 per minute, or one every 3.5 seconds. Meteors sometimes come in pairs or bursts of several, however, with ensuing lulls. Sharp outbursts can occur well before or after a predicted peak.

Important: The city-by-city charts show how many meteors can be expected in a given 15 minute period. See the About the Charts section below.

Finally, all rates quoted on this page are with moonlight taken into account. Many more shooting stars will be up there, but you wont see them. Also, the rates assume dark skies. Your tally will be lower if you live in or near a city.

Charts above show forecasts by three widely respected teams (Asher-McNaught, Jenniskens, Lyytinen-Van Flandern) and were provided by Bill Cooke of NASAs Marshall Space Flight Center.

Importantly, Cooke has generated the charts to show the reduced numbers you can expect to see with moonlight taken into account. Though the rates are given for cities, they reflect what can be expected for many miles around and, in fact, city dwellers wont see these rates because of heavy local light pollution.

The times along the horizontal axis are local times on the morning of Nov. 19 (expressed as 19d). "0h" corresponds to midnight, and "4h" means 4 a.m.

The vertical axis is a bit tricky. Color-coded for each of the three forecast groups, it shows how many meteors are expected in given 15-minute intervals. For example, a line topping out at 250 on your chart means that forecast group expects youll see 250 shooting stars in that 15-minute period, or roughly 16 per minute. Note that a 15-minute rate of 250 equates to the hourly rate of 1,000 discussed above in About the Rates.

Each forecast group uses a slightly different method for figuring out how much debris Earth will encounter, and just how dense the stuff will be at the center of the stream. Their predicted rates, therefore, can very quite a bit. No one can say for sure what you should expect. Go out, look up, and count them for yourself! More on this in What Causes the Leonids.

Hey, my city isnt charted! Dont worry. Rates and times vary only a little for locations within a few hundred miles of each other. Pick a city that is close to you, especially in an east-west sense (longitudinally), and in your time zone.

A nearly full Moon will drown out many faint meteors this year. It will be sinking toward the western horizon as the Sun comes up. [On Friday, Nov. 8, well post tips on exactly how to make the best of the situation.]

Meanwhile, begin thinking about a location with a tree, building or mountain to the west and a clear view to the east.

What Causes the Leonids

The annual Leonid meteor shower is caused by debris left behind by several previous passes of a comet called Tempel-Tuttle as it orbits the Sun every 33 years. On each pass, a different stream is deposited in a slightly different location. Over time, the streams spread out as the material continues orbiting the Sun. Earths orbit crosses these streams, and the debris vaporizes as it rushes through Earths atmosphere.

Most of the material is about the size of sand grains, though some is marble-sized. It can be decades, centuries, or millennia old. Intense showers or storms occur only in years when Earth passes through a dense stream, typically one that has not been around too many decades. Peak rates come when the planet zooms through the center of a stream. [Return Tuesday, Nov. 12 for a complete look at the science of the Leonids.]

This year's expected storm is the last in a series that dates back to 1999 for the Leonids. Forecasters say Earth wont go through a dense Leonid stream again until the year 2033.