Most galaxies take significant fractions of the age of the universe to noticeably change. Others transform themselves in the first two billion years of the universe. How does this happen?
The night sky is now destined to change due to plans which involve placing thousands of satellites into low Earth orbits. Is there a cause for concern?
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.