Dark matter is an invisible form of matter that makes up about 27 percent of the universe, detected only through its gravity. Galaxies spin too fast for the visible matter they contain to hold them together, and galaxy clusters bend light more strongly than their stars and gas can explain. The Bullet Cluster, where the gravitational mass separated cleanly from the ordinary gas during a collision, is among the strongest evidence that dark matter is real and not merely a flaw in our theory of gravity.
Cosmology · Dark Matter · Black Holes
Stars cannot leave a black hole lighter than the Sun. In late 2025 a gravitational-wave detector caught a signal hinting at exactly that, possibly a r...
Space Exploration · ESA · Dark Universe
Ordinary matter, everything we can see, is a rounding error in the cosmos. The rest is dark matter and dark energy. A European space telescope is buil...
Cosmology · Gravitational Lensing · Dark Matter
Mass warps space, and light must follow the curves. Galaxies are smeared into arcs, multiplied into quartets, and bent into perfect rings, a cosmic le...
Cosmology · Dark Matter · Particle Physics
Dark matter and neutrinos are the universe's most elusive residents, each almost incapable of feeling anything. A growing body of cosmological evidenc...
Cosmology · Dark Matter · Galaxy Clusters
When two galaxy clusters smashed through each other, the visible matter slowed and the gravity kept going. The gap between them became the closest thi...
Cosmology · Dark Matter · Black Holes
Supermassive black holes appeared too early and grew too fast for standard physics to comfortably explain. A 2026 study proposes an unlikely culprit: ...