Planet X Cover-Up: Search 3

And more ...

New York Times
January 30, 1983

    Something out there beyond the farthest reaches of the
    known solar system seems to be tugging at Uranus and
    Neptune. Some gravitational force keeps perturbing the
    two giant planets, causing irregularities in their orbits.
    The force suggests a presence far away and unseen, a large
    object that may be the long- sought Planet X. ... The last
    time a serious search of the skies was made it led to the
    discovery in 1930 of Pluto, the ninth planet. But the story
    begins more than a century before that, after the discovery
    of Uranus in 1781 by the English astronomer and musician
    William Herschel. Until then, the planetary system seemed
    to end with Saturn.

    As astronomers observed Uranus, noting irregularities in
    its orbital path, many speculated that they were witnessing
    the gravitational pull of an unknown planet. So began the
    first planetary search based on astronomers predictions,
    which ended in the 1840's with the discovery of Neptune
    almost simultaneously by English, French, and German
    astronomers. But Neptune was not massive enough to
    account entirely for the orbital behavior of Uranus. Indeed,
    Neptune itself seemed to be affected by a still more remote
    planet. In the last 19th century, two American astronomers,
    Willian H. Pickering and Percival Lowell, predicted the size
    and approximate location of the trans-Neptunian body, which
    Lowell called Planet X. Years later, Pluto was detected by
    Clyde W. Tombaugh working at Lowell Observatory in
    Arizona. Several astronomers, however, suspected it might not
    be the Planet X of prediction. Subsequent observation proved
    them right. Pluto was too small to change the orbits of Uranus
    and Neptune, the combined mass of Pluto and its recently
    discovered satellite, Charon, is only 1/5 that of Earth's moon.

    Recent calculations by the United States Naval Observatory
    have confirmed the orbital perturbation exhibited by Uranus
    and Neptune, which Dr. Thomas C Van Flandern, an
    astronomer at the observatory, says could be explained by
    "a single undiscovered planet". He and a colleague, Dr. Richard
    Harrington, calculate that the 10th planet should be two to five
    times more massive than Earth and have a highly elliptical
    orbit that takes it some 5 billion miles beyond that of Pluto -
    hardly next-door but still within the gravitational influence
    of the Sun. ...