Hydrogen can be a metal, but it is only in a solid state under extreme conditions such as being in the core of Jupiter!
The typewriter was invented in 1829, and the automatic dishwasher in 1889.
White dwarf stars can be as small as 1,000 miles across.
The largest island in the Mediterranean sea is Sicily.
Saturn isn't the only planet with rings: Jupiter, Uranus and Neptune have them, too.
Due to its size, Pluto's moon Charon is also considered to be a double dwarf planet (two planets orbiting each other), rather than a moon orbiting its planet.
30 years ago: The computer mouse was invented.
The Earth gets 100 tons heavier every day due to falling space dust.
Hydrofluoric acid will dissolve glass.
The penguin is the only bird who can swim, but cannotfly.