Bill Nye The Science Guy - S01E19 - Outer Space - Best Quality - 4K UPSCALED

How did Eratosthenes figure out that the Earth is round?

• He measured the shadow that a stick cast in Alexandria.
• He traveled from Alexandria to Syene and measured the distance.
• He observed that sticks in Syene cast no shadow at noon on the longest day of the year.
• He studied the movement of stars and planets using astrolabes.

What is the North Star also known as?

• Polaris
• Vega
• Orion
• Cassiopeia

How long does it take for light from the closest star to reach Earth?

• 4.3 years
• 7 hours
• 12,000 years
• Millions and billions of years

What did Eratosthenes realize when he saw that sticks in Alexandria cast a shadow while sticks in Syene did not?

How far apart are the Earth and the sun, if the Earth is represented by a small ball and the sun is represented by a larger ball?

Why do astronomers use astrolabes?

What is something in the text that reminds you of something in your own life?

How do you think learning about outer space can help us understand our own world?

If you could travel to outer space, what would you want to explore and why?