1979J2: The Discovery of a Previously Unknown Jovian Satellite
Abstract
During a detailed examination of imaging data taken by the Voyager 1 spacecraft within 4.5 hours of its closest approach to Jupiter, a shadow-like image was observed on the bright disk of the planet in two consecutive wide-angle frames. Analysis of the motion of the image on the Jovian disk proved that it was not an atmospheric feature, showed that it could not have been a shadow of any satellite known at the time, and allowed prediction of its reappearance in other Voyager 1 frames. The satellite subsequently has been observed in transit in both Voyager 1 and Voyager 2 frames; its period is 16 hours 11 minutes 21.25 seconds ± 0.5 second and its semimajor axis is 3.1054 Jupiter radii (Jupiter radius = 7.14 × 104 kilometers). The profile observed when the satellite is in transit is roughly circular with a diameter of 80 kilometers. It appears to have an albedo of ~ 0.05, similar to Amalthea's.
- Publication:
-
Science
- Pub Date:
- November 1980
- DOI:
- Bibcode:
- 1980Sci...210..786S
- Keywords:
-
- Galilean Satellites;
- Jupiter (Planet);
- Natural Satellites;
- Voyager 1 Spacecraft;
- Voyager 2 Spacecraft;
- Equatorial Regions;
- Satellite-Borne Photography;
- Lunar and Planetary Exploration; Jupiter;
- JUPITER;
- SATELLITES;
- 1979J2;
- DISCOVERY;
- PHOTOGRAPHS;
- IMAGES;
- VOYAGER 1;
- ANALYSIS;
- PERIOD;
- SIZE;
- SHAPE;
- ALBEDO;
- CHARACTERISTICS;
- GEOMETRY