225088 Gonggong

File:225088 Gonggong, artist impression (NASA 2006, color).jpg

Gonggong and its moon Xiangliu (red circle) seen by the Hubble Space Telescope in 2010

225088 Gonggong is a dwarf planet of the Solar System. It is a member of the scattered disc. It has a highly eccentric orbit. It is from 34–101 astronomical units (5.1–15.1 billion kilometers; 3.2–9.4 billion miles) from the Sun. It is the sixth-farthest known Solar System object. Gonggong was discovered in July 2007 by American astronomers Megan Schwamb, Michael Brown, and David Rabinowitz at the Palomar Observatory, and the discovery was announced in January 2009.

Its planetary symbol is 🝽.

Physical characteristics

The surface of Gonggong has an albedo of 0.14. Gonggong is among the reddest trans-Neptunian objects known. Its red color is suprising because it has a lot of water ice on its surface, which are usually neutral in color. Scientists think that there might be methane on its surface which will explain its red color.

Gonggong is estimated to have a diameter of 1,230 km (760 mi). This would make Gonggong the fifth-largest trans-Neptunian object, after Pluto, Eris, Haumea and Makemake. Gonggong is approximately the size of Pluto's moon Charon.

The mass of Gonggong has been calculated to be 1.75×10²¹ kg (3.86×10²¹ lb). It has a density of 1.72±0.16 g/cm³.

Orbit

Gonggong orbits the Sun at an average distance of 67.5 AU (1.010×10¹⁰ km; 6.27×10⁹ mi). It completes a full orbit in 554 years. It has an orbital inclination 30.7 degrees. Its eccentricity is 0.50.

Gonggong is moving away at a speed of 1.1 kilometers per second (2,500 miles per hour). It is the sixth-farthest known Solar System object from the Sun.

Exploration

It was calculated by planetary scientist Amanda Zangari that a flyby mission to Gonggong would take a minimum of over 20 years with the rocket we have today. A flyby mission would be launched on 2030 or 2031.

Moons

Gonggong is known to have a moon, called Xiangliu. The discovery team thought that the slow rotation of Gonggong was caused by a moon.

225088 Gonggong Media

• P48 1994 Jean Large.jpg

  Gonggong was discovered using the Samuel Oschin telescope at Palomar Observatory

• Gonggong symbol (fixed width).svg

  Gonggong symbol (fixed width)

• Gonggong-Neptune resonance (preliminary).gif

  A preliminary motion analysis of Gonggong librating in a 3:10 resonance with Neptune. This animation consists of 16 frames covering 26,000 years. Neptune (white dot) is held stationary.

• Apparent motion of 225088 Gonggong (2000-2050).png

  Apparent motion of Gonggong through the constellation Aquarius (years 2000 to 2050)

• Size Comparison - Gonggong with Earth and Moon.svg

  Size comparison between Gonggong (lower left), alongside Earth (right) and the Moon (upper left).

• Trans-Neptunians Size Albedo Color.svg

  Comparison of sizes, albedo, and colors of various large trans-Neptunian objects with sizes of >700 km. The dark colored arcs represent uncertainties of the object's size.

• Xiangliu orbiting 225088 Gonggong (2009-2010).jpg

  Hubble images of Gonggong and Xiangliu, taken in 2009 and 2010 with the Wide Field Camera 3