Follow your curiosity

What discovery has been shared with you?

FACTREE gives you something interesting to discover every day — and something worth talking about together.

Start with one fact. Explore it, go deeper, then follow whichever branch catches your imagination.

Choose subjects for a surprise

Exploring any topic

Begin your discovery

Your next discovery is one click away.

Choose one or more subjects above, or leave Any Topic selected and let curiosity decide.

Astronomy

Quasars as Active Galactic Nuclei

Quick fact

A single quasar can outshine an entire galaxy of a hundred billion stars, yet its entire energy output comes from a region no larger than our solar system.

Why this is interesting

Looking at the night sky, the brightest stars are often close by. But what if the most brilliant objects in the universe turned out to be the cores of distant galaxies—each powered by a black hole?