According to radiometric dating and other sources of evidence, Earth formed over 4.5 billion years ago.

When astronauts first went into the space, they looked back at the Earth with human eyes for the first time. Based on their observations, the Earth became known as the "Blue Planet". And it's no surprise, since 70% of our planet is covered with oceans.

Earth's average orbital speed is about 30 kilometers per second or 67,000 mph (107,000 km/h).

In 2005, the U.S. Geological Survey's Landsat satellites recorded temperatures in the Lut Desert that measured a stunning 159.3 °F (70.7 °C).

During the formation of the Earth, molten iron sank to its center to make the core. This took with it the vast majority of the planet's precious metals such as gold and platinum. In fact, there is enough gold and other precious metals in the core to cover the entire surface of the Earth four meters thick!

Of all the species that have ever existed on Earth, 99.9 percent are now extinct. Many of them perished in five cataclysmic extinction events. According to a recent poll, seven out of ten biologists think we are currently in the throes of a sixth mass extinction.

The Sun is at an average distance of about 93,000,000 miles (150 million kilometers) from Earth. It is so far away that light from the Sun, traveling at a speed of 186,000 miles (300,000 kilometers) per second, takes about 8 minutes to reach us.

Earth's atmosphere is thickest within the first 50 km from the surface, but it actually reaches about 10,000 km (6,214 miles) into space.

In 2013, analysis of satellite data pinpointed scattered pockets of intensely cold air on the East Antarctic Plateau between Dome Argus and Dome Fuji -- temperatures that dipped to a staggering minus 135 degrees Fahrenheit (minus 93 degrees Celsius).

Earth's atmosphere is 78% nitrogen, 21% oxygen, 0.9% argon, and 0.03% carbon dioxide with trace amounts of neon, helium, methane, krypton and hydrogen.