Professor John Robinson preparing to land on the planet Priplanus using parajets
How many planets did the crew of the Jupiter 2 actually land on? Only three planets are given a name in the scripts. The first is Earth, of course, from which the Jupiter 2 was launched on October 16, 1997. In “Return from Outer Space,” season one, Will returns to Earth using the maser transporter machine left by the Taurons in “The Sky Is Falling.” Dr. Smith and Will make a near approach to Earth again in season two’s “Rocket to Earth,” but do not land. The Jupiter 2 lands on Earth once more in “Visit to a Hostile Planet” and “Target: Earth” in season three. The first planet the crew lands on after leaving Earth (in the season one episode “Island in the Sky”) is called Priplanus by Will later that season in “Return from Outer Space.” In the season three episode "Collision of the Planets," it turns out that the planet they find themselves on is called Kromah by the civilisation sending the space hippie wrecking crew to destroy it.
The two planets visited by the Jupiter 2 in season two may be given descriptive names based on their location or inhabitants. The first such planet might be called the Mechanized Planet, where the crew land in the episode of the same name in (and referred to as such by the Robot in the following episode). In the fourth episode of the same season, “The Forbidden World,” they arrive at the Sector 6:30 Planet, where they remain until the first episode of the third season, “Condemned of Space.”
During the first two seasons, therefore, the Robinsons with Major West, Dr. Smith, and the Robot visit the Earth, Priplanus, the Mechanized Planet, and the Sector 6:30 Planet—four in all. Most of their adventures during these two seasons take place on Priplanus and the Sector 6:30 Planet.
In season three, episode one, “Condemned of Space,” the Jupiter 2 lifts off from the Sector 6:30 Planet and arrives at the Verah Castle space prison. How many more planets did the Jupiter 2 reach after that? The answer depends on the continuity you choose. Regardless of the continuity, it must be borne in mind that landings or take offs logically required by a particular sequence are not always shown in the episodes.
Following the order in which the episodes were filmed, the Robinsons touch down on twelve more planets (not counting the Earth in “Visit to a Hostile Planet”), for a total of 16 different planets over the three years of the series’ run.
1. Hunter’s Moon Planet (“Hunter’s Moon,” “The Space Primevals”)
2. Unnamed Planet 1 (“Deadliest of the Species”)
3. The Emerald Planet, so named because of the visuals (“Flight into the Future,” “The Space Destructors,” “The Haunted Lighthouse”)
4. Kromah (“Collision of the Planets”)
5. Unnamed Planet 2 (“The Anti-Matter Man,” “Castles in Space,” “A Day at the Zoo,” “Two Weeks in Space”)
6. Gilt Proto’s Planet (“Target: Earth”)
7. The Sobram’s Planet (“The Flaming Planet”)
8. Unnamed Planet 3 (“The Time Merchant,” “Princess of Space”)
9. Delta (“The Promised Planet”)
10. The Vegetable Planet (“The Great Vegetable Rebellion”)
11. Unnamed Planet 4 (“Fugitives in Space,” “Space Beauty”)
12. Junkyard Planet (“Junkyard in Space”)
Looking at the episodes in the order of their original air dates, one arrives at a different total. Here, we have the crew of Jupiter 2 visiting ten new planets.
1. Hunter’s Moon Planet (“Hunter’s Moon,” “The Space Primevals,” “The Space Destructors,” “The Haunted Lighthouse”)
2. Kromah (“Flight into the Future,” “Collision of the Planets”)
3. Unnamed Planet 1 (“Deadliest of the Species,” “A Day at the Zoo,” “Two Weeks in Space,” “Castles in Space,” “The Anti-Matter Man”)
4. Gilt Proto’s Planet (“Target: Earth”)
5. Unnamed Planet 2 (“Princess of Space,” “The Time Merchant”)
6. Delta (“The Promised Planet”)
7. Unnamed Planet 3 (“Fugitives in Space,” “Space Beauty”)
8. Sobram’s Planet (“The Flaming Planet”)
9. Vegetable Planet (“The Great Vegetable Rebellion”)
10. Junkyard Planet (“Junkyard in Space”)
Are there any other possibilities? If we are free to reorder the episodes after “Condemned of Space,” it is possible to arrive at another number of new planets visited by the Robinsons. In the following list, eight new planets are reached. In this list, the the Robinsons are shown arriving on all of the planets given, but taking off from only the Hunter’s Moon Planet and the Emerald Planet. Or course, their intention of leaving all but the unnamed planet is, in fact, explicit in the episodes concerned. Only two episodes (73 and 78) are taken out of broadcast order.
1. Hunter’s Moon Planet (“Hunter’s Moon,” “The Space Primevals,” “The Space Destructors,” “The Haunted Lighthouse”)
2. Kromah (“Flight into the Future,” “Collision of the Planets”)
3. Unnamed Planet 1 (“Deadliest of the Species,” “A Day at the Zoo,” “Two Weeks in Space,” “Castles in Space,” “The Anti-Matter Man,” “Princess of Space,” “The Time Merchant,” “Fugitives in Space,” “Space Beauty”)
4. Gilt Proto’s Planet (“Target: Earth”)
5. Delta (“The Promised Planet”)
6. Sobrams’ Planet (“The Flaming Planet”)
7. Vegetable Planet (“The Great Vegetable Rebellion”)
8. Junkyard Planet (“Junkyard in Space”)
In any of the above lists, I have not taken into account those episodes in season three when the entire story takes place in space, or, in “Creature from Space,” where there is no landing (either by the ship or the space pod) on a planet. Of course, the crew of the Jupiter 2 did not experience life only in outer space or on alien worlds. On many occasions members of the crew found their adventures in other dimensions. Maybe another fan would like to list those episodes…Cheers
Nelson1959