- There is also an asteroid called 548 Kressida.
 | |
| Discovery | |
|---|---|
| Discovered by | Stephen P. Synnott / Voyager 2 |
| Discovery date | January 9, 1986 |
| Mean orbit radius | 61,766.730 ± 0.046 km[1] |
| Eccentricity | 0.00036 ± 0.00011[1] |
| Orbital period | 0.463569601 ± 0.000000013 d[1] |
| Inclination | 0.006 ± 0.040° (to Uranus' equator)[1] |
| Satellite of | Uranus |
| Physical characteristics | |
| Dimensions | 92 × 74 × 74 km[2] |
| Mean radius | 39.8 ± 2 km[2][3][4] |
| Surface area | ~20,000 km²[5] |
| Volume | ~260,000 km³[5] |
| Mass | ~3.4 × 1017 kg[5] |
| Mean density | ~1.3 g/cm³ (assumed)[3] |
| Equatorial surface gravity | ~0.013 m/s2[5] |
| Escape velocity | ~0.034 km/s[5] |
| Rotation period | synchronous[2] |
| Axial tilt | zero[2] |
| Albedo | 0.08 ± 0.01[6] 0.07[3][4] |
| Temperature | ~64 K[5] |
Cressida (pronounced /ˈkrɛsɨdə/ KRES-i-də) is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 1986-01-09, and was given the temporary designation S/1986 U 3.[7] It was named after the Trojan daughter of Calchas, a tragic heroine who appears in William Shakespeare's play Troilus and Cressida (as well as in tales by Geoffrey Chaucer and others). It is also designated Uranus IX.[8]
Cressida belongs to the Portia Group of satellites. Which includes Bianca, Desdemona, Juliet, Portia, Rosalind, Cupid, Belinda and Perdita.[6] These satellites have similar orbits and photometric properties.[6] Unfortunately, other than its orbit,[1] radius of 41 km[2] and geometric albedo of 0.08[6] virtually nothing is known about it.
At the Voyager 2 images Cressida appears as an elongated object, the major axis pointing towards Uranus. The ratio of axises of the Cressida's prolate spheroid is 0.8 ± 0.3.[2] Its surface is grey in color.[2]
Cressida may collide with Desdemona within the next 100 million years.[9]
0 comments:
Post a Comment