... To help answer this, scientists instructed the robot spacecraft Galileo to take hourly pictures of this moon of Jupiter prior to its most recent encounter. The most obvious changes in Io are due to the changing amount of sunlight reflected from the moon to the spacecraft. X-Ray Earth . ... Dark Bok Globules in IC 2944 . ... The dark spots in the above picture are not photographic defects but an unusual type of interstellar cloud known as a Bok globule. ... CG4: A Ruptured Cometary Globule . ...