This NASA web page refers to the SF film The Man from Planet X (1951) in reference to the possibility of a planet at earth's L3 point - directly opposite the sun:

NASA is unlikely to find any use for the L3 point since it remains hidden behind the Sun at all times. The idea of a hidden "Planet-X" at the L3 point has been a popular topic in science fiction writing. The instability of Planet X's orbit (on a time scale of 150 years) didn't stop Hollywood from turning out classics like The Man from Planet X.

You can read this question's sibling question if you like, but my question here is:

Did the film The Man from Planet X (1951) refer to a planet that was (at least at one time) in an orbit similar to the earth but on the opposite side of the sun?

note: This was the case in another SF film: Journey to the Far Side of the Sun (1969).


2 Answers 2


No, the planet in the film "The Man from Planet X" is extra-solar in origin. The aliens, suffering from a lack of heat from their home star used a process of

"selective de-gravitation"

to wrench their planet out of its usual orbit and throw it towards our Solar system. Their urgent need to invade Earth is prompted by the fact that if they fail to do so at the point that the Earth is on its closest approach, their planet will continue off into the void and freeze solid.

As you can see in the opening sequence, we see the Professor using his telescope to look directly at the planet which is described as

"rushing out of space toward us"

something that clearly couldn't be accomplished if it was hidden behind the sun.

enter image description here

  • This is why I asked the question in the first place. NASA is pretty good about trying to avoid saying things that are factually wrong (even if it's summarizing a SF story), and yet I know that in the film, Planet X passes by earth. It is possible that in the plot it was historically behind the sun and unobserved, but due to some instability it slowly drifted along it's orbit closer and closer to earth. Otherwise it would have been frozen in the cold of space, far from a sun. I don't have access to the film itself, so I'm looking for detailed information about the plot, or subplot, or subtext.
    – uhoh
    Commented Feb 6, 2016 at 19:04
  • OH! Interesting link - I'm going to look into this... Thank You!
    – uhoh
    Commented Feb 6, 2016 at 19:09
  • OK indeed you are correct! Thanks for the enhanced synopses. I'll watch the rest, but so far I have: Reporter: "What is it?" Astronomer: "A new planet. For want of another name it is presently identified as Planet X. It was first spotted some weeks ago rushing out of space." Thank you again for taking the time to help me out!
    – uhoh
    Commented Feb 6, 2016 at 19:19
  • 1
    @uhoh - There's a little more info in the final conversation with the Professor. I've added it into the answer.
    – Valorum
    Commented Feb 6, 2016 at 19:23
  • Great - I have added a link to your answer to this question's sibling question in another universe (ok, another stack exchange).
    – uhoh
    Commented Feb 6, 2016 at 19:33

To the second part of your question, in the Independent 2011 film Another Earth a second Earth is discovered in the solar system. While not explicitly called out as such, presumably it has been hidden in the L3 position to have gone unnoticed.

Too, the Wiki site for Another lists Journey to the Far Side of the Sun as one of the likely influences for the film.

In the movie

Also similar to Journey to the Far Side of the Sun, it is eventually discovered that the 'other' Earth is a true duplicate which had identical events right up until each side discovered one other. Though, unlike Journey, it is not a true 'reversed' mirror image.

  • Thank you @beichst - this is helpful! So far I haven't found any information on the 1951 film (Man from Planet X) and have no idea even whee to start looking.
    – uhoh
    Commented Feb 6, 2016 at 18:33
  • If you are simply seeking information about the film, Wiki has a pretty good summary: en.wikipedia.org/wiki/The_Man_from_Planet_X
    – beichst
    Commented Feb 6, 2016 at 18:39
  • Is the answer to my question in that article - I did not see it there. I want to know if - in this film - the planet is ever behind the sun. I'm not sure that article has a definitive answer to this question.
    – uhoh
    Commented Feb 6, 2016 at 18:48
  • 1
    That I do not know. As you indicated, neither Wiki (nor IMDB) seem to explicitly reference the idea of Planet X being an L3 planet. Only the NASA site seems to do that.
    – beichst
    Commented Feb 6, 2016 at 18:52
  • There are other films about duplicate Earths on the opposite side of the Sun: [ Doppelgänger](en.wikipedia.org/wiki/Doppelg%C3%A4nger_(1969_film)) and [Journey to the Far Side of the Sun[(imdb.com/title/tt0064519)
    – Barmar
    Commented Aug 5, 2023 at 18:24

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