Astronomy

Fate of the Galaxy

For Milky Way, past is prologue.

The Milky Way has a bright future ahead of it — literally — predicts Ohio State University astronomer Stelios Kazantzidis.

Using computer models, he concludes that, in the far future, the host of smaller satellite galaxies that orbit the Milky Way will merge with it. When they do, the gravitational forces will puff up the Milky Way’s stars and other matter to create luminous stellar rings, or flares.

Many scientists expect this merger. They speculate, however, that it would tear the Milky Way apart — one tough break for whatever life forms inhabit the galaxy at the time.

Kazantzidis’s computer models are based on the real-life movements of other galaxies similar to the Milky Way, and project a much more hopeful future.

“The satellite galaxy impacts don’t destroy spiral galaxies. They actually drive their evolution,” he says.

It is an evolution that has already been going on for billions of years, he adds. The continuous pull from the satellite galaxies might explain why the Milky Way has its namesake nebulous haze.

“Every spiral galaxy has a complex formation and evolutionary history,” says Kazantzidis. “We would hope to understand exactly how the Milky Way formed and how it will evolve. We may never succeed in knowing its exact history, but we can try to learn as much as we can about it.” — Rick Docksai

Source: Stelios Kazantzidis, www.ohio-state.edu.