Most of the universe is slipping away from the Milky Way, carried outward as space itself expands. Yet one giant neighbor is bucking the trend, racing straight at us while almost every other major ...

For decades, scientists have theorized that the Milky Way Galaxy’s supermassive black hole, known as Sagittarius A* (Sgr A*), ...

In space, the gravitational pull of massive objects is irresistible to smaller ones. Moons are locked in orbit around planets. Planets, asteroids and comets orbit more massive stars, and stars collect ...

A hundred years ago, astronomer Edwin Hubble dramatically expanded the size of the known universe. At a meeting of the American Astronomical Society in January 1925, a paper read by one of his ...

The distance between the Milky Way and Andromeda in 50 simulations. Just slightly more than half of orbits result in a Milky Way - Andromeda collision within 10 billion years. Sharp features in ...