269 Justitia
Shape of Justitia as seen by stellar occultation observations on 31 August 2023 | |
| Discovery | |
|---|---|
| Discovered by | Johann Palisa |
| Discovery site | Vienna Obs. |
| Discovery date | 21 September 1887 |
| Designations | |
| (269) Justitia | |
| Pronunciation | /dʒʌˈstɪʃiə/ |
Named after | Justitia |
| A887 SA 1942 XY | |
| Main belt (middle) · background | |
| Orbital characteristics | |
| Epoch 5 May 2025 (JD 2460800.5) | |
| Uncertainty parameter 0 | |
| Aphelion | 3.179 AU |
| Perihelion | 2.048 AU |
| 2.613 AU | |
| Eccentricity | 0.2164 |
| 4.22 yr (1,543 d) | |
| 244.365° | |
| 0° 13m 59.88s / day | |
| Inclination | 5.477° |
| 156.503° | |
| 120.144° | |
| Physical characteristics | |
| Dimensions | 64.60 × 58.34 × 46.60 km ± (2.86 × 2.64 × 2.60 km): 6 |
| 57.0–57.8 km (occultation) 58±2 km (thermophysical) | |
| 33.12962 ± 0.00001 h (1.38040083 ± 4.2×10−7 d) | |
| 171°±15° (to ecliptic) | |
Pole ecliptic latitude | −81°±15° |
Pole ecliptic longitude | 73°±11° |
| 0.072±0.007 (occultation) 0.058±0.006 (thermophysical) | |
| RR or IR (TNO classification) Z-type asteroid Ld-type (SMASSII classification) D-type (Bus–DeMeo classification) | |
| 12–15 | |
| 9.82 | |
269 Justitia is an asteroid located in the middle main asteroid belt. It was discovered on 21 September 1887 by Austrian astronomer Johann Palisa at Vienna Observatory and was named after Justitia, the Roman goddess of justice. The asteroid is about 58 kilometres (36 mi) in diameter and rotates relatively slowly, with a rotation period of 33.1 hours. Justitia is one of the targets of the United Arab Emirates' upcoming MBR Explorer mission, which will visit seven different asteroids in the asteroid belt during the 2030s. MBR Explorer is planned to enter orbit around Justitia via rendezvous in 2034 and will end its mission after dropping a lander to the asteroid's surface in 2035.
Justitia is unusual in that it has a much redder color compared to any other asteroid in the asteroid belt. Spectroscopic observations show that Justitia's color and composition appears to resemble those of centaurs and trans-Neptunian objects from the outer Solar System, whose surfaces are composed of ices and complex organic compounds (tholins). Hence, researchers believe that Justitia originated from the outer Solar System and then migrated inward to its present-day location in the asteroid belt. Only a few other asteroids have been identified to exhibit very red colors like Justitia, with 203 Pompeja and 732 Tjilaki as examples from the main asteroid belt.