Bad news: the odds of our galaxy smashing into Andromeda just jumped back up to 90%.
March 25, 2026
Original Paper
The Fate of the Milky Way--Andromeda System: To Merge or Not?
arXiv · 2603.22863
The Takeaway
A recent study suggested our galaxy's collision with Andromeda was a 50/50 coin toss, but new calculations including the gravity of nearby satellite galaxies restore the 'classic' prediction of a near-certain smash-up in about 6.5 billion years.
From the abstract
It has long been predicted that the Milky Way (MW) will eventually merge with Andromeda (M31), a view reinforced by \textit{HST} measurements indicating a small M31 transverse velocity. However, using updated \textit{Gaia}-based proper motions (PMs) and including the dynamical influence of the Large Magellanic Cloud (LMC) and M33, Sawala et al. reported an MW--M31 merger probability of $\sim$50\% within 10 Gyr, leaving the fate of the Local Group (LG) uncertain. Adopting their semi-analytic fram