How certain is a Milky Way–Andromeda merger over the next 10 billion years, according to a 2025 Hubble and Gaia study?

The answer

The 2012 Hubble story called a head-on smashup destiny. Sawala and colleagues folded in Gaia, the LMC, and M33 and got roughly even odds of a merger within 10 billion years. A 4–5 billion-year head-on hit is only a few percent. Stars still almost never collide if the galaxies do merge.

Correct answer: About 50-50; a merger is no longer treated as inevitable