Does any planet, or Kuiper Belt Object, or exoplanet measured or surmised, orbit its star either fast enough, or slow enough and thus distantly enough to cast a long enough shadow, for a spacecraft to orbit it in permanent umbra? (Earth doesn't.)

  • $\begingroup$ I see you've deleted this answer perhaps out of concern that it's short and link-only-ish. But it's stimulated some interesting discussion in comments that are no longer available to anybody to continue, and completely invisible to lower-rep users. That's of course just how things go in SE and certainly not your problem, but I wonder if you might consider undeleting and just adding say one more sentence describing what's in your link, thereby allowing the discussion to continue? $\endgroup$
    – uhoh
    Commented Dec 9, 2021 at 23:52
  • 1
    $\begingroup$ I'd deleted it because the comments clarified that that technology is inappropriate for this situation, so as an answer it was plain wrong. I'll undelete it now, with an edit to that effect, at least so nobody else falls into the same trap. Thanks for the nudge. $\endgroup$ Commented Dec 10, 2021 at 0:01
  • $\begingroup$ if you get any flak about it, you are 100% welcome to say it's all uhoh's fault. :-) $\endgroup$
    – uhoh
    Commented Dec 10, 2021 at 0:05

1 Answer 1


Jupiter's L2 point is 53.94 million km behind it.
The L2 point "orbits" the planet on a 1-Jupiter-year cycle, exactly
(just about by definition)

From there Jupiter is 0°8'55" wide, and the sun is 0°5'45" wide.

Jupiter casts a permanent shadow on its L2 point.


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