Jupiter to several seconds, and short bursts (or S-bursts) that had a duration of less than a hundredth of a second. Scientists discovered that there were three forms of radio signals transmitted from Jupiter. Since 1973 a number of automated spacecraft have visited Jupiter, most notably the "Pioneer 10" space probe, the first spacecraft to get close enough to Jupiter to send back revelations about the properties and phenomena of the Solar System's largest planet. Flights to other planets within the Solar System are accomplished at a cost in energy, which is described by the net change in velocity of the
The Phantom Planet The Phantom Planet The Phantom Planet is a 1961 independently made American black-and-white science fiction film, produced by Fred Gebhardt, directed by William Marshall, that stars Dean Fredericks, Coleen Gray, Anthony Dexter, and Francis X. Bushman. The film was released in the U.S. by American International Pictures as a double feature with "Assignment Outer Space". In 1980, the United States Air Force's Space Exploration Wing has bases on the Moon, and it is on the eve of a mission to Mars. When another of its two-member crew Pegasus spacecraft mysteriously disappears, rumors begin circulating of space monsters and phantom planets.