Star light, star bright ... better yet, a satellite

In four minutes, the Russians are coming.

Dusk passes on this cold, still day just after winter solstice, and Russ Pinizzotto directs a visitor to look skyward. Venus blazes to the southwest, but Mr. Pinizzotto peers in the general direction of Mars, and waits.

Right on schedule, a celestial occurrence of the man-made kind: Cosmos 1222, a satellite lobbed up in the waning days of the cold war, ambles across the sky like a slow-motion meteor without a tail. "There," says Mr. Pinizzotto, not bothering to raise his binoculars.

Minutes later, in a different orbit, comes the discarded body of the rocket that launched it. And then, knifing brightly across the constellation Cassiopeia, a Lacrosse 4 US radar satellite.

"People are surprised," says Pinizzotto. "They ask, 'What night can I see a satellite?' No, it's 'How many satellites can I see on any given night?' "

Pinizzotto logged 40 one summer evening from a lawn chair in Maine. The dean of science and engineering at Merrimack College here, he's also an avid satellite observer, one in a subset of skygazers who like their astronomy with an earthbound twist.

Part bird-watchers, part train-spotters, these people know their star charts. But they are as likely to rhapsodize about a sighting of the International Space Station, XM Radio's geostationary duo (dubbed "Rock" and "Roll"), or an iridium flare (a flash of reflected sunlight from a communications satellite) as they are to gush about a glimpse of Saturn's rings.

This game is as old as Sputnik, and it can often be played from any dark spot with the unaided eye. (Warning: It's hard to stop.) But participants' skills have improved along with sky-tracking software and good, inexpensive telescopes and mounts.

Hobbyists can share and network on the Web. Heavens-above.com, for example, provides a remarkably simple guide to the galaxy, complete with local satellite-viewing times organized by magnitudes of brightness and showing precise trajectories.

Amateurs contributed some of the data in a major aggregation of satellite specifics posted online last month by the Union of Concerned Scientists, according to Laura Grego, a staff scientist for the Cambridge, Mass., organization. As part of its push for public awareness of space-based government activities, the UCS (ucsusa.org/satellite_database) lists some 800 active satellites by launch date, country of origin, sponsor, and orbital coordinates. It ignores inactive satellites and other space junk.

"There are many thousands of things in this [junk] category ... from large, spent, rocket bodies and abandoned satellites to small bolts and bits of paint," says Dr. Grego. The rate of launches has declined since the 1990s, which saw about 125 a year. But in five years, she figures, 1,000 actives will be in orbit - more traffic for space shuttles to negotiate.

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