Asteroid Ida and her moon Dactyl
On August 28, 1993, Galileo spacecraft snapped this photo of the asteroid Ida and captured an image that helped NASA scientists discover her moon, Dactyl. The picture was taken about 14 minutes before Galileo made its closest approach to Ida on its way to Jupiter.
Ida was discovered by Johann Palisa in September 1884. Dactyl, named for the creatures that inhabited Mount Ida in Greek mythology, is about 90 km from Ida. It measures about 1.6km x 1.4km x 1.2km.