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

The Effect of Solar Energetic Particles on the Mars Atmosphere

Quick fact

A single SEP event can double Mars's atmospheric density at high altitudes, and the induced auroras have been observed by spacecraft like MAVEN.

Why this is interesting

The Sun's wilder tantrums can actually change the atmosphere of Mars, billions of miles away — but not the way you'd expect. Imagine a swirling storm of invisible particles smashing into a planet's delicate gas blanket.