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

How Magnetospheres Shield Planetary Atmospheres from Stellar Energetic Particles

Quick fact

Mars, which lost its global magnetic field billions of years ago, is losing its atmosphere even today: the solar wind strips about a kilogram per second of gas from its atmosphere.

Why this is interesting

Our planet is constantly bombarded by charged particles from the Sun—yet we barely notice it because of an invisible shield. But what if that shield disappeared?