Roanoke Times
                 Copyright (c) 1995, Landmark Communications, Inc.

DATE: TUESDAY, June 1, 1993                   TAG: 9306010004
SECTION: NATIONAL/INTERNATIONAL                    PAGE: A-4   EDITION: METRO 
SOURCE: The New York Times
DATELINE:                                 LENGTH: Short

PLANET X? NOT IN THIS SOLAR SYSTEM

For a half century stargazers have hunted for Planet X, the solar system's hypothetical 10th planet. Its existence was inferred from what appeared to be irregularities in the orbital motions of several known planets. But a new study of the outer planets indicates that the long chase, based on presumed wobbles in the orbits of Uranus and Neptune caused by a planet, was based on erroneous calculations.

The apparent death blow to the Planet X theory was published in the May issue of The Astronomical Journal by Dr. E. Myles Standish Jr., an astrophysicist at the Jet Propulsion Laboratory in Pasadena, Calif.

His analysis, the first to make use of a new measurement of Neptune's mass made by Voyager 2 in 1989, shows that the outer planets are moving just as one would expect if there were no planet beyond them exerting a gravitational tug on their orbits.