Astronomers had predicted many skywatchers in North America and Europe might see one or two shooting stars per minute, during bursts when the hourly rate would hover around 60.

"I have been following both the Perseid and Leonid showers for years now and from my experience, this was the most disappointing shower," said Alan Stankevitz, who lives in a dark-sky location near La Crosse, Wisconsin. "The sky conditions could not have been better, too. Unfortunately, the Leonids never showed up as expected."

Stankevitz estimates the Leonids never produced more than about 20 visible meteors per hour. Other, fainter meteors may have gone unseen. Astronomers predicted this year's show might involve a lot of faint shooting stars produced by very small particles.

"This year's Leonid meteor shower was meager," said Tony Phillips, who operates the NASA-run web site Spaceweather.com. "In most places, people saw fewer than 10 meteors per hour -- much less than predicted.

Nobody can yet say why. But the Leonids have always proved difficult to forecast. Astronomers try to figure out which of many ancient debris trails, left on each 33-year orbit by comet Tempel-Tuttle, Earth might pass through.

"Perhaps Earth missed the anticipated comet debris trail," Phillips said. "Or we hit it and the meteors were too faint to make an impression."

• Leonids Special Report