New Planet Lurking in the Shadows of the Kuiper Belt?

Scientists at the Lunar and Planetary Laboratory at the University of Arizona have discovered a gravitational anomaly in the outer reaches of the Kuiper Belt, an icy region on the outskirts of the solar system, which could point to the existence of a “planetary mass body”. If found to be a planet, the object could well be considered a tenth planet of the solar system, in spite of its tremendous distance from the Sun: The planetary mass body lies more than ten times as far from the Sun as Pluto.

The body was discovered because of its gravitational effect on the orbital plane of distant Kuiper Belt objects (KBO). Kuiper Belt objects have a tilted orbital plane, but icy space rocks in the outer reaches of the Belt have been shown to exhibit a differing orbital plane. While the average of the numerous Kuiper Belt bodies follows the invariable plane of the solar system, the outer reaches exhibit a deviation of about 8 degrees. The relatively high tilt angle of the orbital plane means a planetary mass at least as large as Mars could be nearby.

How Do We Study These Objects?

While gathering information about outer Kuiper Belt objects has been difficult so far, the development of the Large Synaptic Survey Telescope in Chile is likely to help scientists study the farthest reaches of the solar system in greater detail. The Kuiper Belt is so far away from the Earth that even the most developed technologies at our disposal at present are insufficient for studying it, but the LSST could raise the number of observed Kuiper Belt objects from 2,000 to nearly 40,000. While most Kuiper Belt objects still remain too dark for telescopes to study, the more detailed perspective offered by advanced lenses will help scientists make much more accurate projections.