Star, planet, moon, constellation or galaxy?
Look at thirteen things in the sky, from the Sun and Dhruvatara to Venus, Saptarishi and the Milky Way. Find out whether each makes its own light and how far away it is, then sort them.
Core concept
Stars are huge balls of hot gas that make their own light; planets and moons shine by reflected sunlight; a constellation is a pattern of stars seen from the Earth, and a galaxy is a vast collection of billions of stars
Topic: Universe
On a clear night far from city lights, Nepal's sky is full of points of light, but they are not all the same kind of thing. Stars, like our Sun, are huge balls of hot gas that make their own light. Planets, like Venus and Jupiter, go round the Sun and shine only because sunlight bounces off them. Moons go round planets and also reflect sunlight. A constellation is a pattern of stars as seen from the Earth, such as Saptarishi (the Great Bear); its stars only look close together and may be very different distances away. A galaxy is a huge collection of billions of stars: we live in the Milky Way. Distances in space are measured in light-years: the distance light travels in a year, about 9.5 million million km.
What you will learn
- Distinguish between stars, planets, moons, constellations and galaxies.
- Explain the difference between making light and reflecting it.
- Define a light-year and use it to compare distances.
- Name constellations seen from Nepal and use Saptarishi to find the Pole Star.
Before you start
- Know the planets of the solar system.
Materials
- A star chart for the month, or a sky map app
Equipment
- Binoculars, if you have them
Procedure
- Pick a card and find out its light and its distance.
- Do this for at least eight cards.
- Sort every card into star, planet, moon, constellation or galaxy.