(243) Ida

from Wikipedia, the free encyclopedia
(243) Ida
Asteroid Ida with moon Dactyl
Asteroid Ida with moon Dactyl
Properties of the orbit ( animation )
Epoch:  April 18, 2013 ( JD 2,456,400.5)
Orbit type Outer main belt
Asteroid family Koronis family
Major semi-axis 2,862  AU
eccentricity 0.042
Perihelion - aphelion 2.743 AU - 2.981 AU
Inclination of the orbit plane 1.1 °
Length of the ascending node 324 °
Argument of the periapsis 110 °
Time of passage of the perihelion March 9, 2011
Sidereal period 4 a 308 d
Mean orbital velocity 17.6 km / s
Physical Properties
Medium diameter 59.8 × 25.4 × 18.6 km
Dimensions 4.12 x 10 16Template: Infobox asteroid / maintenance / mass kg
Albedo 0.2383
Medium density 2.5 g / cm³
Rotation period 4 h 38 min
Absolute brightness 9.94 mag
Spectral class S.
Explorer Johann Palisa
Date of discovery September 29, 1884
Source: Unless otherwise stated, the data comes from JPL Small-Body Database Browser . The affiliation to an asteroid family is automatically determined from the AstDyS-2 database . Please also note the note on asteroid items.

(243) Ida is an asteroid of the main asteroid belt that was discovered on September 29, 1884 by Johann Palisa at the Vienna University Observatory.

The asteroid was named after the nymph Ida from Greek mythology.

Ida is an irregularly shaped, elongated body with a mean diameter of 31.4 kilometers. It has a light, silicate-rich surface.

On August 28, 1993, the Galileo space probe passed the asteroid at a distance of 10,500 km and sent CCD images to Earth. The images show that the celestial body is covered by impact craters . Large parts of the asteroid are covered by a layer of dust, the regolith .

It was also shown that Ida is orbited by a small natural satellite . This moon, only 1.4 km in size, was named Dactyl and was the first asteroid moon to be observed.

Ida from different sides
Flyby images that begin 5.4 hours before the pass show the rotation

See also

Web links

Commons : Ida (Asteroid)  - album with pictures, videos and audio files