Though scientists have been looking for Planet X for 100 years, the possibility that it's real got a big boost recently when researchers from Caltech inferred its existence based on orbital anomalies seen in objects in the Kuiper Belt, a disc-shaped region of comets and other larger bodies beyond Neptune.
If the Caltech researchers are correct, Planet X is about 10 times the mass of Earth and could currently be up to 1,000 times more distant from the sun Whitmire and his colleague, John Matese, first published research on the connection between Planet X and mass extinctions in the journal Nature in 1985 while working as astrophysicists at the University of Louisiana at Lafayette.
While this chapter does not go into specific geologic hazard assessment techniques, most of which are well beyond the technical, temporal, and budgetary constraints of integrated development planning studies, it presents and discusses existing information which can and should be used during the Preliminary Mission and Phase I stages of a planning study.
This information is sufficient to show the planning team whether a hazard constitutes a significant problem in development area and, if so, what detailed studies requiring the services of a specialist are needed.
Whitmire and Matese published their own estimate on the size and orbit of Planet X in their original study.