52 Europa
3D model of Europa based on lightcurve modeling
|
|
| Discovery | |
|---|---|
| Discovered by | H. Goldschmidt |
| Discovery date | February 4, 1858 |
| Designations | |
| MPC designation | (52) Europa |
| Pronunciation | /jʊˈroʊpə/ ew-ROH-pə |
|
Named after
|
Europa |
| 1948 LA | |
| Main belt | |
| Orbital characteristics | |
| Epoch November 26, 2005 (JD 2453700.5) | |
| Aphelion | 3.417 AU (511.201 Gm) |
| Perihelion | 2.785 AU (416.621 Gm) |
| 3.101 AU (463.911 Gm) | |
| Eccentricity | 0.102 |
| 5.46 yr (1994.629 d) | |
|
Average orbital speed
|
16.87 km/s |
| 70.730° | |
| Inclination | 7.466° |
| 128.992° | |
| 343.553° | |
| Physical characteristics | |
| Dimensions | (379±16)×(330±8)×(249±10) km (mean: 315±7 km) 360×315×240 km |
| Mass | 3.27×1019 kg |
|
Mean density
|
1.5 ± 0.4 g/cm³ |
| ~0.14 m/s² | |
| ~0.2 km/s | |
| 0.2347 d | |
| Albedo | 0.058 |
| Temperature | ~173 K max: 258K (−15 °C) |
|
Spectral type
|
C-type asteroid |
| 6.31 | |
52 Europa is the 6th-largest asteroid in the asteroid belt, having an average diameter of around 315 km. It is not round but is shaped like a triaxial ellipsoid of approximately 380x330x250 km. It was discovered on February 4, 1858, by Hermann Goldschmidt from his balcony in Paris. It is named after Europa, one of Zeus's conquests in Greek mythology, a name it shares with Jupiter's moon Europa.
Europa is approximately the sixth largest asteroid by volume. Most likely it has a density of around 1.5 g/cm³, typical of C-type asteroids. In 2007, James Baer and Steven R. Chesley estimated Europa to have a mass of (1.9±0.4)×1019 kg. A more recent estimate by Baer suggests it has a mass of 3.27×1019 kg.
Europa is a very dark carbonaceous C-type, and is the second largest of this group. Spectroscopic studies have found evidence of olivines and pyroxenes on the surface, and there is some indication that there may be compositional differences between different regions It orbits close to the Hygiea asteroid family, but is not a member.
Lightcurve data for Europa have been particularly tricky to interpret, so much so that for a long time its period of rotation was in dispute (ranging from 5 and a half hours to 11 hours), despite numerous observations. It has now been determined that Europa is a prograde rotator, but the exact direction in which its pole points remains ambiguous. The most detailed analysis indicates that it points either towards about ecliptic coordinates (β, λ) = (70°, 55°) or (40°, 255°) with a 10° uncertainty. This gives an axial tilt of about 14° or 54°, respectively.
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Wikipedia