Our Galaxy and Stars: Distances in Space

The video tutorial explains how distances are measured on Earth using kilometers or miles and introduces the concept of measuring distances in space. For nearby celestial objects like the moon or sun, kilometers are used. However, for distant stars like Rigel, which is 861 trillion kilometers away, astronomers use light years. A light year is the distance light travels in one year, approximately 9.5 trillion kilometers. The video also discusses the speed of light, which is 310,000 kilometers per second, and how this measurement helps in calculating astronomical distances.

What units are typically used to measure distances on Earth?

• Parsecs

• Astronomical units

• Kilometers or miles

• Light years

Why are kilometers not practical for measuring vast distances in space?

• They are not recognized internationally

• They are too small for such distances

• They are not accurate enough

• They are only used for measuring time

What is a light year?

• The time it takes for light to travel around the Earth

• The time it takes for light to reach the moon

• The distance light travels in one year

• The speed of light in a vacuum

How fast does light travel?

• 150,000 kilometers per second

• 350,000 kilometers per second

• 300,000 kilometers per second

• 310,000 kilometers per second

How far is the star Rigel from Earth in light years?

• 861 light years

• 910 light years

• 950 light years

• 1000 light years