Despite such a black hole being several thousand times smaller than any of the planets, its mass would be several thousand times greater. Thus, any planets unfortunate enough to be caught in its path would be devoured.
By the time the black hole reached the asteroid belt between Mars and Jupiter, things would look bleak for us. The intense gravitational pull of the black hole would have torn our planet asunder, causing devastating earthquakes and supervolcanoes the likes of which humanity has never witnessed before. Upon reaching Earth’s orbit our planet is all but doomed, reduced to a smoldering uninhabitable magma-laden rock, with Mercury and Venus soon following suit.
The final battle, between the black hole and the Sun, wouldn’t be quite so one-sided. A gravitational tug of war would ensue and, depending on the initial mass of the black hole, there’s a chance the Sun could survive in some shape or form. Unfortunately, the most likely scenario is that, like the planets, the Sun is ripped apart and joins the planets in the swirling mass of super-heated dust and gas roaring around the black hole.