I was reading a closed question with the same title and wondered if it would be on-topic with the following change:

  1. Could a large-mass object from interstellar space pass through the inner solar-system in such a way as to capture the Earth and it's moon (or substantially all their debris) causing them to be removed from the inner solar system within a short time relative to the motions of the planets with respect to one another.

  2. If 1 is possible and occurred at a time in the next 1000 years when Earth is furthest from the nearest planets, in what way would the orbits of other planets in the inner solar system be measurably altered or perturbed in the 1000 years following that event?

I'm only seeking a broad-brush answer understandable to the general public.

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    $\begingroup$ Not in a realistic scenario. In order to minimize the disturbance to the system, the intruder would have to be very fast. An ultrafast (close to relativistic?) impactor penetrating from above or below the ecliptic may scatter most of the debris in the forward direction, which could than leave the system as a jet of hot plasma. Such an object could be small and fast enough to not cause much of a disturbance. But where are you getting a small planet size body moving at a percent of the speed of light or faster? $\endgroup$
    – CuriousOne
    Commented Oct 16, 2014 at 20:56
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    $\begingroup$ Why? What's with this recent compulsion to raise dead questions? Let the dead questions rest in peace. $\endgroup$ Commented Oct 16, 2014 at 21:54
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    $\begingroup$ If you're just interested in the effect on the rest of the system, why not drop the issue of how exactly the Earth disappeared, and just ask about the future behavior of a hypothetical system in which the masses, orbits, and initial positions/velocities at time t0 of the Sun/other planets/asteroids/etc. are identical to what they are right now in our solar system, but no Earth-analogue is present? Then you could ask whether the future evolution of this system will differ significantly from the future evolution of ours, arbitrarily far in its future. $\endgroup$
    – Hypnosifl
    Commented Oct 17, 2014 at 0:13
  • $\begingroup$ @CuriousOne Where would I get such a body? Why, I'd ask Marco Inaros, of course! ;-) $\endgroup$ Commented Nov 29, 2021 at 16:19

1 Answer 1


If you take something like Neptune and pass it through Earth's orbit perpendicular to the ecliptic so it collides directly with the Earth-Moon system at, lets say, 0.1c you would remove the Earth rather quickly. Get another if you want to disappear the moon as well. Neptune isn't so big that it would disturb everything else, maybe a wobble in Venus or Mars unless, as you say, they are on the other side of the sun.

As the chances of this happening are right up there with "action of a vengeful God" we may as well just have the God magically disappear the Earth system and be done with it.

Net effect on the rest of the solar system: not much. We are an extremely small mass in comparison to the gas bodies, it's possible that Venus and Mars will move a bit but not so much that you would be able to work out why. Mercury is totally dominated by the sun, Jupiter won't notice.

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    $\begingroup$ +1 Watch out for that vengeful god. Especially given the old testament tales of his bad hair days. $\endgroup$ Commented Oct 17, 2014 at 0:14

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