(119951) 2002 KX14
A flattened Kuiper belt object with a possible large moon.
Wikipedia / Wikimedia Commons
(119951) 2002 KX14 is a trans-Neptunian object in the inner classical Kuiper belt. Astronomers Michael E. Brown and Chad Trujillo discovered it on 17 May 2002 at Palomar Observatory, while scanning for Pluto-sized bodies beyond Neptune. The object is highly flattened: its equatorial diameter measures 482 km (300 mi) and its maximum polar diameter is 314 km (195 mi). Its surface is dark and reddish, probably due to a coating of tholins. There is indirect evidence that 2002 KX14 may have one large moon, though no direct observations have confirmed it.
**History**
**Discovery** 2002 KX14 was found on 17 May 2002 by Chad Trujillo and Michael Brown at Palomar Observatory in San Diego County, California. It was part of their Caltech Wide Area Sky Survey, which used the observatory’s 1.22-meter (48 in) Samuel Oschin telescope and its wide-field CCD camera, operated alongside the nightly Near Earth Asteroid Tracking program. That survey also discovered other large objects beyond Neptune, including the dwarf planets Eris, Sedna, and Quaoar. The object was identified by manually checking potential moving objects flagged by the team’s automated image-searching software. It appeared at a red-filter apparent magnitude of 20.6, just brighter than the survey’s limit of 20.7. Follow-up observations were made one month later, on 13–14 June 2002, using Palomar’s 1.52-meter (60 in) telescope. The Minor Planet Center announced the discovery on 20 July 2002, assigning the provisional designation 2002 KX14.
**Further observations and occultations** After the discovery announcement, astronomers continued observing 2002 KX14 and found pre-discovery images: Cerro Tololo Observatory had recorded it in August 2001, and the Digitized Sky Survey at Siding Spring Observatory had captured it in May 1984 and April 1993. These earlier observations improved the orbit’s accuracy. As of 2025, 2002 KX14 has been observed for more than 38 years, roughly 16% of its orbital period. As of 2026, the object lies in the Milky Way’s galactic plane, a star-dense region that complicates rotation-period measurements but increases the chance of stellar occultations—events where 2002 KX14 passes in front of a star, allowing precise measurements of its size, shape, and position. The first such occultation was observed on 26 April 2012 by the William Herschel Telescope at La Palma Observatory. Between
- discovery_date
- 17 May 2002
- discoverers
- Michael E. Brown and Chad Trujillo
- location
- Palomar Observatory
- category
- trans-Neptunian object, inner classical Kuiper belt object
- equatorial_diameter
- 482 km
- polar_diameter
- 314 km
- orbital_period
- 241 years
Lore & Background
2002 KX14 was discovered as part of the Caltech Wide Area Sky Survey for bright, Pluto-sized Kuiper belt objects, using the 1.22-meter Samuel Oschin telescope at Palomar Observatory. The discovery was announced by the Minor Planet Center on 20 July 2002. Pre-discovery observations from Cerro Tololo Observatory (August 2001) and Siding Spring Observatory (May 1984 and April 1993) helped refine its orbit. As of 2025, the object has been observed for over 38 years.
Stellar occultations have revealed that 2002 KX14 is highly flattened, with an equatorial diameter of 482 km and a maximum polar diameter of 314 km. Its surface is dark and reddish, with a geometric albedo of 0.119, and spectroscopy shows a featureless spectrum consistent with tholins. A 2021 study estimated its surface composition as 20% water, 60% silicates, and 20% organics.
Indirect evidence from thermal emission measurements suggests 2002 KX14 may have a moon about 251 km in diameter, though Hubble Space Telescope images from 2006 and stellar occultation observations from 2020 to 2023 did not directly detect it. The object's rotation period remains unknown due to low brightness variations and its location in the Milky Way's dense star fields.
Reader's Guide
2002 KX14 is significant as one of the largest known cold classical Kuiper belt objects, with a highly flattened shape that suggests it may be a Maclaurin spheroid in hydrostatic equilibrium. Its dark reddish surface, likely covered with tholins, provides clues about the chemical processes on primitive bodies in the outer Solar System. The indirect evidence for a large moon—about two-thirds its own diameter—raises questions about binary formation via streaming instability or impact. However, the moon remains unconfirmed, and the object's rotation period is unknown, limiting understanding of its density and internal structure. Its location in the inner classical Kuiper belt, with a low orbital inclination and eccentricity, places it among dynamically cold classical KBOs, though some astronomers argue it may belong to the hot population. Continued occultation observations may resolve its shape, rotation, and possible satellite, offering insights into the early Solar System's planetesimal population.
Did You Know?
- 2002 KX14 has an equatorial diameter of 482 km and a polar diameter of 314 km, making it highly flattened.
- Its surface is dark and reddish, likely covered with tholins formed by irradiation of ices.
- Indirect thermal emission evidence suggests it may have a moon about 251 km in diameter, though not directly observed.
- The object's rotation period is unknown because its brightness varies by less than 0.05 magnitudes.
Frequently Asked Questions
Who discovered (119951) 2002 KX14?
Michael E. Brown and Chad Trujillo identified this object on 17 May 2002 while conducting surveys at Palomar Observatory, specifically searching for Pluto-sized bodies beyond Neptune.
What type of object is (119951) 2002 KX14?
It is a trans-Neptunian object classified as an inner classical Kuiper belt body, orbiting the Sun in a relatively undisturbed region well beyond Neptune.
What is unusual about (119951) 2002 KX14's shape?
The body is strikingly oblate, measuring roughly 482 km across its equator but only 314 km pole to pole, giving it a distinctly flattened, pancake-like profile.
Does (119951) 2002 KX14 have a moon?
Indirect evidence hints at the presence of one large satellite, but no direct observational confirmation of a moon has been recorded to date.
What does (119951) 2002 KX14's surface look like?
Its surface appears dark and reddish, a coloration most likely produced by tholin compounds that build up over long exposure to solar radiation.
More in Discoveries by Michael E. Brown 1-24
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