These are serious questions I have (tho they might be incredibly stupid). I know the rotations of the different planets are not the same, so my question is this. Will there ever be a time when the Earths rotation around the sun (vs another planets rotation), make it so the Earth's night sky will no longer see that planet? As in, the planet is on the other side of the sun from the earth, and is hidden completely by the sun and thus, there could be a time in the future where no matter where you are on the planet, you wouldn't be able to locate Neptune, or Uranus in the sky. In relation to that question, are all the planets on the same plane? By that I mean, their rotation ellipses. The visuals that are shown of the rotations (rudimentary as they are) suggest they're all on the same plane. Are they?
Not stupid at all. The ability to see a celestial object in the night sky is called an "apparition". Mercury, for instance, is frequently "behind the sun" from us, so its apparition length is only a matter of days at a time. Mars' is a couple of years at a time. Additionally, a celestial body can be "behind the moon" or "occulted" from time to time. Yes. Due in large part to angular momentum of the sun, all of the planets are within about 6 degrees of the solar ecliptic (basically, if you took the equator of the sun and extrapolated that out into space. The inner planets are all just about at +/- 1 degree.
Thanks for answering. I meant for long stretches of time, but didn't put it in the post. Like, will there be a time when people won't be able to see a planet for a long time, maybe yars, not just a few days or whatever.
Generally, no. Our rotation around the sun means that there will always be a time (within, say, a 4-year period) where we'll catch up with a sun-obstructed celestial object. In fact, I think Mars is the one that is occluded the longest, but that's just a guess.
