• The Big Bang, or formation of the Universe happened about 13.8 billion years ago. The Sun formed 4.6 billion years ago and Planet Earth about 4.54 billion years ago.
• Earth orbits the sun once every 365.25 days. As we set our calendar year to 365 days, we add an extra day every 4 years to settle the difference.
• Earth hurtles through space at an average speed of 29.6 km (18.5 miles) a second.
• Our planet is not as big as you might think. It only has a diameter of 13,000 km (8,000 miles).
• Earth’s core consists of 88.8 percent iron, 5.8 percent nickel, 4.5 percent sulfur and less than 1 percent other stuff, including oxygen.
• Earth’s atmosphere is about 480 km (300 miles) thick. It contains 5 main layers: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
• Ozone is a naturally occurring gas that resides in our atmosphere, occurring mainly in the lower stratosphere. It is important because it protects us from ultraviolet solar radiation, which can cause skin cancer and eye damage.
• When Krakatoa volcano erupted on August 27, 1883, it caused the largest volcanic tsunami in history. It was formed in less than a minute after the eruption, and grew to be 40 meters tall. It is estimated to have killed over 36,000 people.