253 Mathilde
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| Discovery | |
|---|---|
| Discovered by: | Johann Palisa |
| Discovery date: | November 12, 1885 |
| Alternative names: | A915 TN; 1949 OL1 |
| Minor planet category: | Main belt |
| Orbital characteristics | |
| Epoch January 30, 2005 (JD 2453400.5) | |
| Aphelion distance: | 501.179 Gm (3.350 AU) |
| Perihelion distance: | 290.685 Gm (1.943 AU) |
| Semi-major axis: | 395.932 Gm (2.647 AU) |
| Eccentricity: | 0.266 |
| Orbital period: | 1572.683 d (4.31 a) |
| Avg. orbital speed: | 17.98 km/s |
| Mean anomaly: | 288.854° |
| Inclination: | 6.738° |
| Longitude of ascending node: | 179.642° |
| Argument of perihelion: | 157.458° |
| Physical characteristics | |
| Dimensions: | 66×48×46 km |
| Mass: | 1.033×1017 kg |
| Mean density: | 1.3 g/cm³ |
| Equatorial surface gravity: | 0.0096 m/s² |
| Escape velocity: | 0.0225 km/s |
| Rotation period: | 17 d 9 h 30 min |
| Albedo: | 0.04 |
| Temperature: | ~174 K |
| Spectral type: | C |
| Absolute magnitude: | 10.2 |
253 Mathilde is a Main belt asteroid that was visited by the NEAR Shoemaker spacecraft on its way to asteroid 433 Eros. It is a primitive C-type asteroid, the first such asteroid to be visited by a spacecraft. It is also currently the largest asteroid to be visited by a spacecraft.
[edit] Description
Mathilde is very dark, and is thought to share the same composition as carbonaceous chondrite meteorites. The density measured by NEAR Shoemaker, 1,300 kg/m³, is less than half that of a typical carbonaceous chondrite; this may indicate that the asteroid is very loosely packed rubble pile.[1] The same is true of several C-type asteroids studied by ground-based telescopes equipped with adaptive optics systems (45 Eugenia, 90 Antiope, 87 Sylvia, 121 Hermione)
The asteroid has a number of extremely large craters; several are wider than the asteroid's average radius. No differences in brightness or colour were visible so the asteroid's interior must be very homogeneous.
Mathilde's orbit is eccentric, taking it to the outer reaches of the Main belt. It also has one of the slowest rotation periods of the known asteroids. Because of that NEAR Shoemaker was not able to photograph all of the asteroid's surface.
It was discovered by Johann Palisa on November 12, 1885 in Vienna.
Mathilde is believed to be named after the wife of astronomer Moritz Loewy.
[edit] See also
[edit] References
- ^ Yeomans DK, Barriot J, Dunham DW, Farquhar RW, Giorgini JD, Helfrich CE, Konopliv AS, McAdams JV, Miller JK, Owen WM Jr, Scheeres DJ, Synnott SP, Williams BG (1997). "Estimating the mass of asteroid 253 Mathilde from tracking data during the NEAR flyby". Science 278 (5346): 2106-9. PMID 0009405343.
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|---|---|---|
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| List of asteroids | ||
Vulcanoids · Near-Earth asteroids · Main belt · Jupiter Trojans · Centaurs · Damocloids · Comets · Trans-Neptunians (Kuiper belt • Scattered disc • Oort cloud)
For other objects and regions, see Asteroid groups and families, Binary asteroids, Asteroid moons and the Solar System.
For a complete listing, see List of asteroids. See also Pronunciation of asteroid names and Meanings of asteroid names.
