EntryEarth

At some point in the past, scientists discovered an anomaly in the Earth's sun which was burning through its fuel at a much faster rate than normal. As a result, the star would begin expanding and possibly turn into a super nova in a drastically close time (within one-thousand years).

The citizens of Earth built three ships and left the planet, but by the time they settled the Three Empires and developed technology to get back faster, the sun had already expanded and destroyed the planet.