If dark matter did not exist, the visible matter in the universe should be able to explain all gravitational phenomena. But can it?
The early universe is a period of intense star formation across nearly all galaxies. Is it possible tell these galaxies apart from each other, when the universe was less than a few billion years old?
Massive galaxies arise by the time the universe is less than half its current age. Wait four billion more years, and by how much do these galaxies grow? The answer may surprise you.
Galaxy clusters act like cosmic telescopes, magnifying our view of the universe. These exceptionally massive structures allow astronomers to gaze deep into the cosmos and study galaxies during early ages of the universe in fantastic detail. With the completion of the Frontier Fields survey, we can now study a population of magnified, distant galaxies like never before.