Discovered by R. Luther Pronunciation /ˈθiːtᵻs/ THEE-tis Adjectives Thetidian Discovered 17 April 1852 Spectral type S-type asteroid Named after Thetis | Discovery date April 17, 1852 Minor planet category Main belt Orbital period 1,418 days Orbits Sun Discoverer Robert Luther | |
 | ||
Alternative names A913 CA; A916 YF;
1954 SO1 Similar Robert Luther discoveries, Other celestial objects | ||
Asteroid 17 thetis
17 Thetis is a large main-belt asteroid that was discovered by R. Luther on April 17, 1852. It was his first asteroid discovery. The name comes from Thetis, the mother of Achilles in Greek mythology.
Contents
One Thetidian stellar occultation was observed from Oregon in 1999. However, the event was not timed.
The spectrum of this object indicates that it is an S-type asteroid with both low and high calcium forms of pyroxene on the surface, along with less than 20% olivine. The high-calcium form of pyroxene forms 40% or more of the total pyroxene present, indicating a history of igneous rock deposits. This suggests that the asteroid underwent differentiation by melting, creating a surface of basalt rock.
Mass
The mass of Thetis has been calculated from perturbations by 4 Vesta and 11 Parthenope. In 2007, Baer and Chesley calculated Thetis to have a mass of 1.2×1018 kg with a density of 3.21 g/cm³.