2018 VG18
2018 VG18 is a distant trans-Neptunian object (TNO) that was discovered when it was 123 AU (18 billion km; 11 billion mi) away from the Sun, more than three times the average distance between the Sun and Pluto. It was discovered on 10 November 2018 by Scott Sheppard, David Tholen, and Chad Trujillo during their search for TNOs whose orbits might be gravitationally influenced by the hypothetical Planet Nine. They announced the discovery of 2018 VG18 on 17 December 2018 and nicknamed the object "Farout" to emphasize its distance from the Sun.
Discovery images of 2018 VG18 | |
| Discovery | |
|---|---|
| Discovered by | S. S. Sheppard D. Tholen C. Trujillo |
| Discovery site | Mauna Kea Obs. |
| Discovery date | 10 November 2018 |
| Designations | |
MPC designation | 2018 VG18 |
Alternative designations | "Farout" (nickname) |
Minor planet category | TNO · SDO resonant (2:9) · distant |
| Orbital characteristics (barycentric) | |
| Epoch 25 February 2023 (JD 2460000.5) | |
| Uncertainty parameter 6 | |
| Observation arc | 16.15 yr (5,900 d) |
| Earliest precovery date | 21 November 2003 |
| Aphelion | 124.897±0.043 AU (occurs 2063) |
| Perihelion | 38.358±0.030 AU |
Semi-major axis | 81.628±0.028 AU |
| Eccentricity | 0.5301±0.0004 |
Orbital period (sidereal) | 737.01±0.38 yr |
Mean anomaly | 157.653°±0.473° |
Mean motion | 0° 0m 4.814s / day |
| Inclination | 24.292°±0.002° |
Longitude of ascending node | 245.325°±0.001° |
| ≈ 1696 ±30 years | |
| 16.865°±0.171° | |
| Physical characteristics | |
Mean diameter | 656 km (albedo 0.12) 500 km (est.) |
| 24.6 | |
| 3.94±0.52 | |
2018 VG18 is the second-most distant natural object ever observed in the Solar System, after 2018 AG37 (132 AU), which was also discovered by Sheppard's team in January 2018. As of 2024, 2018 VG18 is 123.6 AU (18 billion km) away from the Sun and is moving farther away until it reaches aphelion in 2063. While 2018 VG18 is one of the most distant Solar System objects known, its orbit is nowhere near being the most distant since its average orbital distance from the Sun is 82 AU, which places it in the scattered disk and the 2:9 orbital resonance with Neptune. Little is known about 2018 VG18's physical properties other than its pinkish color, which indicates an ice-rich surface.