In a special issue(1) of Astronomy magazine, Steve Nadis ponders the long-term fate of not only our galaxy, but of the universe itself, based on recent data. By projecting from the currently accepted model that the universe is constantly expanding, some astrophysicists are concluding that the mysterious dark matter that now composes 70% of the universe, will eventually encompass 97% of the total, "rendering matter insignificant in the grand scheme of things," he writes.
The sun will grow so large in about a billion years that life on Earth "will no longer be an option," Nadis notes. Yet, if humanity does manage to migrate to other planets, here is the long (as in very long) range forecast:
Pictured: The "Egg Nebula" taken by the Hubble Telescope