Mangrove trees can desalinate seawater — their roots filter out up to 90% of salt.

Lightning can heat air hotter than the surface of the Sun.

The crash of a thunderclap is a sonic boom — the superheated air expands faster than sound.

Sharks existed before trees.

Volcanic ash can damage engines and machinery.

The largest man-made hole in the world is the Bingham Canyon copper mine in Utah — 4 km wide and 1.2 km deep.

Altruism — acting for others' benefit at a cost to yourself — challenges purely self-interested models of human nature.

The tallest waterfall, Angel Falls in Venezuela, has a continuous drop of 807 meters.

Lightning can strike more than once in the same place.