There are seven continents: Africa, Antarctica, Asia, Australia, Europe, North America, and South America. (But according to a new study published by the Geological Society of America, New Zealand may actually be the tip of a submerged 8th continent, not just an island. Some scientists are calling it "Zealandia.")

With a density of 5.513 g/cm³, Earth is the densest planet in the Solar System and the largest of the four terrestrial planets.

We are currently in the Holocene Epoch of the Quaternary Period of the Cenozoic Era.

Among all animals, ants outweigh us in biomass -- putting billions and billions of tons up against humans' fewer than 500 million. And while they're both tiny and lacking a backbone, krill are the champs among animals worldwide, in terms of numbers, with a population estimated at 500 trillion.

At more than 200m high, 150m wide and 5km long, the Hang Son Doong cave in Vietnam is so big it has its own river, jungle and climate. In fact, some of its caverns are large enough to hold a 40-story skyscraper!

3753 Cruithne, sometimes called "Earth's second moon", is a Q-type, Aten asteroid in orbit around the Sun in 1:1 orbital resonance with Earth, making it a co-orbital object. Cruithne orbits the Sun in about 1 year but it takes 770 years for the series to complete a horseshoe-shaped movement around the Earth.

Pangaea was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from earlier continental units approximately 335 million years ago and began to break apart about 175 million years ago.

The temperature at the Earth's core may be up to 10,830 °F (6,000 °C), and the pressure could reach 360 GPa (52 million psi).

The nearly continuous, global Mid-Ocean Ridge system snakes across the Earth's surface like the seam on a baseball. It stretches 40,389 miles.

If you could separate the Earth out into piles of material, you'd get 32.1% iron, 30.1% oxygen, 15.1% silicon, and 13.9% magnesium. Of course, most of this iron is actually located at the core of the Earth. If you could drill down and sample the core, it would be 88% iron.