StarDate 5/21/2014: Looking For Distant Neighbors

FROM THE UNIVERSITY OF TEXAS McDONALD OBSERVATORY, AS HEARD ON KCBS RADIO WEEKDAYS @ 9:52 A.M., 7:35 P.M. & 2:52 A.M.

STARDATE 5/21/2014: The hinterlands of our solar system are tough to study. The objects beyond the realm of the planets are so far and small that it's difficult to even find them. That difficulty is highlighted by a couple of recent studies.

A space telescope known as WISE spent more than a year mapping the sky at infrared wavelengths. One of its goals was to look for large but faint companions far from the Sun. Some have suggested that a companion periodically disturbs the cloud of comets at the edge of the solar system, sending some of them racing toward the Sun, where they could possibly hit Earth.

WISE could have detected the infrared glow of a companion star or brown dwarf within several light-years of the Sun, or a giant planet out to many thousands of times the distance from Earth to the Sun. But a thorough analysis of its observations found no hint of such objects.

But a study with a ground-based telescope detected evidence of a big planet much closer to the Sun.

Using a giant new camera attached to a telescope in Chile, two astronomers discovered a possible dwarf planet that stays billions of miles beyond the big planets.

The orbit of this object is similar to those of a few other small, distant bodies. The astronomers say that suggests that a larger body may be pushing them around — a planet much heavier than Earth, but smaller than the solar system's giants. If so, then a big world may await discovery in the distant solar system.