Earth, which is almost round in shape, measures 24,901 miles (39,842 kilometers) around at its widest part, the equator. (The equator is the imaginary line that crosses the planet midway between the North and South Poles.) A measurement through Earth at the equator in other words, the planet’s diameter reveals that it is 7,926 miles (about 12,700 kilometers) across. Earth’s weight, or mass (the amount of matter it is made of), is around 6 sextillion tons. That is 6 with 21 zeros after it! Because Earth cannot be put on an enormous scale to find its weight, scientists use the laws of gravity and mathematical equations to figure this out.
- How old is Earth?
- Will people live in space one day?
- What was the Challenger disaster?
- What is the space station Skylab?
- When were animals sent up in space?
- How many U.S. astronauts have walked on the Moon?
- Can astronauts drink soda in space?
- Which is the windiest planet?
- Who was the first African American in space?
- Who was the first woman in space?
- Who was the first man in space?
- What does a satellite do?
- What are space probes?
- What has the Hubble Space Telescope discovered?
- What do the astronauts wear in space?
- What is a space shuttle?
- When did the first spacecraft go up into space?
- What is the U.S. Census?
- How does a rocket blast off?
- Where in space could you ice skate?
