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

Stars vs. Sand Grains: The Scale of the Universe

Quick fact

The estimated number of stars in the observable universe (about 10^24) is comparable to—or even greater than—the estimated number of sand grains on all the world's beaches (about 10^20 to 10^24).

Why this is interesting

Have you ever tried to count the grains of sand on a beach? Now imagine every beach on Earth—then imagine that each grain of sand could be a star. How do these numbers compare?