Astronomers have discovered relics of merger events in the Milky Way halo. Five small groups of stars appear to represent mergers with smaller galaxies, while a big 'blob' comprising hundreds of stars appears to be the remnant of a large merger event.
Pinning down the mass of a galaxy may seem like an esoteric undertaking, but scientists think it holds the key to unraveling the nature of the elusive, yet-to-be-seen dark matter, and the fabric of our cosmos.
One of the unsolved mysteries in modern science is why the expansion of the universe appears to be accelerating. As astrophysicists look for answers in the mountains of data gathered from astronomical observations, they are finding that inconsistencies in that data might ultimately lead to the truth.
Astronomers have inventoried a sizable share of the universe's stars, galaxies, comets, and black holes. But are planets with sustainable civilizations also something the universe contains? Or does every civilization that may have arisen in the cosmos last only a few centuries before it falls to the climate change it triggers?