Planet X Cover-Up: Search 1

Going into the discovery of Planet X by the IRAS team in late 1983,
here’s what was said about the search.

Astronomy
Search for the Tenth Planet
Dec 1981

    Astronomers are readying telescopes to probe the outer
    reaches of our solar system for an elusive planet much
    larger than Earth. Its existence would explain a
    160-year-old mystery. ... The pull exerted by its gravity
    would account for a wobble in Uranus' orbit that was
    first detected in 1821 by a French astronomer, Alexis
    Bouvard. Beyond Pluto, in the cold, dark regions of
    space, may lie an undiscovered tenth planet two to five
    times the size of Earth. Astronomers at the U.S. Naval
    Observatory (USNO) are using a powerful computer to
    identify the best target zones, and a telescopic search
    will follow soon after. ... Van Flandern thinks the tenth
    planet may have between two and five Earth masses and
    lie 50 to 100 astronomical units from the Sun. (An
    astronomical unit is the mean distance between Earth and
    the Sun.) His team also presumes that, like Pluto's, the
    plane of the undiscovered body's orbit is tilted with
    respect to that of most other planets, and that its path
    around the Sun is highly elliptical.

Astronomy
Searching for a 10th Planet
Oct 1982

    The hunt for new worlds hasn't ended. Both Uranus and
    Neptune follow irregular paths that observers can explain
    only by assuming the presence of an unknown body whose
    gravity tugs at the two planets. Astronomers originally
    though Pluto might be the body perturbing its neighbors,
    but the combined mass of Pluto and its moon, Charon, is
    too small for such a role. ... While astronomers believe that
    something is out there, they aren't sure what it is.  Three
    possibilities stand out: First, the object could be a planet -
    but any world large and close enough to affect  the orbits of
    Uranus and Neptune should already have been spotted.
    Searchers might have missed the planet,  though, if it's
    unusually dark or has an odd orbit. ...

    NASA has been recording velocities for a year now and will
    continue for as long as necessary. This past spring, it
    appeared that budget cuts might force the end of the
    Pioneer project. The space agency now believes that it will
    have the money to continue mission operations. Next year,
    the JPL group will begin analyzing the data. By the time
    the Pioneer experiment shows results, an Earth-orbiting
    infrared telescope may have discovered the body. ... Together,
    IRAS and the Pioneers will allow astronomers to mount a
    comprehensive search for new solar system members. The
    two deep space probes should detect bodies near enough to
    disturb their trajectories and the orbits or Uranus and Neptune.
    IRAS should detect any large body in or near the solar system.
    Within the next year or two, astronomers may discover not
    one new world, but several.