The Milky Way along with its neighbours, Andromeda (shown in image) and the Triangulum galaxies – also known as M31 and M33 – make up most of the mass of the Local Group. Image credit: NASA/ESA, J. Dalcanton (University of Washington, USA)/B. F. Williams (University of Washington, USA)/L. C. Johnson (University of Washington, USA)/the PHAT team/R. Gendler
The European Space Agency’s (ESA) Gaia satellite has looked beyond our galaxy and explored two nearby galaxies to reveal the stellar motions within them and how they will one day interact and collide with the Milky Way – with surprising results.
Our Milky Way belongs to a large gathering of galaxies known as the Local Group and, along with the Andromeda and Triangulum galaxies – also referred to as M31 and M33, respectively – makes up the majority of the group’s mass.
Astronomers have long suspected that Andromeda will one day collide with the Milky Way, completely reshaping our cosmic neighbourhood. However, the three-dimensional movements of the Local Group galaxies remained unclear, painting an uncertain picture of the Milky Way’s future.
“We needed to explore the galaxies’ motions in 3D to uncover how they have grown and evolved, and what creates and influences ...