Today is the fiftieth anniversary of the dawn of the Space Age: On October 4, 1957, the U.S.S.R. launched Sputnik 1 (shown at left), the first artificial satellite, from the Baikonur Cosmodrome in what is now Kazakhstan. Sputnik, just 23 inches in diameter, orbited the Earth every 96 minutes, its beeping radio signal causing excitement among ham radio operators and anxiety among American officials whose attempts to launch a satellite had thus far met with failure. Sputnik re-entered the atmosphere and burned up around January 4, 1958. The launch of Sputnik spurred the space race between the U.S. and U.S.S.R. that within 12 years would put astronauts on the Moon. (To see another image of Sputnik, look at today's Google logo.)

As if to mark this anniversary, in the early evening tonight the International Space Station (with its joint Russian and American crew) will be visible along the Eastern seaboard, passing nearly overhead for people in the New York area to see, weather permitting--and the prospects are fairly good.

It requires no special equipment; in fact, it will be brighter than any other star or planet. Predictions have it slightly brighter than the planet Jupiter, but the predictions are usually conservative, so it could even rival Venus (which won't be visible) in brightness.

Observers elsewhere on or near the East Coast should go to the Heavens Above Web site, enter their location and time zone, and go to the link for 10-day predictions for ISS. The chart for October 4 will give the times of the ISS's appearance, greatest altitude, and disappearance, direction to look in, and altitude in degrees, with 0 degrees being the horizon and 90 degrees the zenith.

The action for New Yorkers begins and ends shortly before 8 p.m. The station will appear around 7:56, rising steeply in the southwest and looking like a moving star that brightens as it climbs. Just before 7:59, it will be at its highest and presumably brightest, 80 degrees high (nearly overhead; 90 degrees would be directly overhead) for observers in New York City, even higher for people on Long Island or Connecticut, slightly lower for people in New Jersey but still nearly overhead. About 15 seconds later, the International Space Station will disappear abruptly when it passes into Earth's shadow.

Post by Tony Hoffman