Submitted by Matthew Bothwell on Wed, 10/06/2026 - 16:33
Many congratulations to Professor Vasily Belokurov, of the Institute of Astronomy, who has been awarded the Kavli Prize in Astrophysics for 2026 along with Amina Helmi and Rodrigo Ibata “for uncovering the fossil evidence of past mergers proving that the Milky Way galaxy was built through hierarchical accretion.”
"The recipients have used the remnants of devoured galaxies to prove that our galaxy is the survivor of enormous, billion year old cosmic collisions, giving us a revolutionary view of how our universe is formed," says Per Barth Lilje, Chair of the Kavli Prize Committee in Astrophysics.
For decades, the Milky Way was seen as a stable, beautiful spiral. The 2026 Kavli Prize Laureates in Astrophysics -- Amina Helmi, Vasily Belokurov, and Rodrigo Ibata -- have overturned this idea.
Using the most precise instruments available, the scientists have effectively performed cosmic archaeology. They have analysed vast, stretched-out structures of stars, known as stellar streams. These are the visible wreckage of smaller dwarf galaxies ripped apart by the Milky Way's gravity, providing a detailed record of the galaxy's history of mergers.
This work has shifted the paradigm of galaxy formation from a slow, steady state to a dynamic, violent narrative of galactic cannibalism.
Most importantly, these streams act as cosmic seismometers. By measuring how the stars are moving, scientists are mapping the galaxy's gravitational potential, allowing them to chart the distribution and structure of the elusive dark matter — the invisible scaffolding that holds the Milky Way together.
The discoveries have also fundamentally altered how we conceive of the universe: galaxies are not just collections of stars; they are living historical objects, constantly being born, damaged, and rebuilt by the gravitational dance of massive cosmic mergers.
