A million years from now Alph Centauri will no longer be the nearest star system to our own because?

Question

A million years from now Alph Centauri will no longer be the nearest star system to our own because?

Answer 1

... because it will have moved to about 100 light years away from us.  It is only about 4.4 light years from us now.  There are about 80,000 other stars within 200 light years, so one of them will be the closest in a million years.

Somebody would have to go through the whole list of 80,000 stars to figure out which one will be closest by then.

Answer 2

Because the solar system is constantly moving, galaxies pushing against each other are causing the solar system to expand.

Answer 3

The universe is expanding.

Answer 4

Stars have their own proper motion.  Even though all the stars you can see are orbiting the galaxy's core, they do move in their own independent paths, in all directions from the sun. Alpha Centauri is moving away from us at 21.6 km/sec.  In a million years, it will be 72 light years away.

(Expansion of the universe has nothing to do with it.)

Answer 5

Because our solar system is both moving through the galaxy and is not gravitationally bound to Alpha Centauri.

Answer 6

Who knows! The way the drift around our solar system is, some other star in the constellation of Hercules or Ophiuchus will pass by our system to within 3 light years by then.