A Welcome Conclusion

The news that Caltech astronomers have concluded that Pluto is really a planet after all and not an asteroid is most welcome, in large part because it retains for Clyde W. Tombaugh the distinction of being the only 20th-Century person to have discovered a planet.

Tombaugh was a 22-year-old neophyte astronomer working at the Lowell Observatory in Flagstaff, Ariz., in 1930 when he spotted a planet--which turned out to be Pluto--among 400,000 stars in photographs of the sky that he had taken. He is now a professor emeritus of astronomy at New Mexico State University, Las Cruces, and the story of his discovery of Pluto through hardwork and cleverness is still one of the many remarkable tales of recent science. There is so much sky to be observed that amateur and beginning astronomers can make important contributions to the field.

The existence of a ninth planet had been predicted by Percival Lowell, the great American astronomer and founder of the observatory, but he died in 1916.

It remained for Tombaugh, a Kansas farm boy who liked looking at the stars, to study the photographs and find the tiny planet, whose motion differed from the stars around it.

His accomplishment would have suffered if it now turned out that what he found was only an asteroid.