Tools for studying stars
With just our eyes we can see thousands of stars, but most look like tiny dots. To learn more, scientists use tools. Binoculars gather more light than the eye and show many more stars. An optical telescope has large mirrors or lenses that collect even more light, so very faint and faraway objects can be seen clearly. Stars also send out waves we cannot see. Radio telescopes collect radio waves, and other instruments study other kinds of light. A spectrograph splits starlight into colours to tell what a star is made of. Air makes starlight twinkle and blocks some kinds of light, so some telescopes are launched into space above the air. The Hubble Space Telescope has been orbiting Earth since 1990, and the James Webb Space Telescope is much farther out. Astronauts do not travel to the stars because they are too far away. The most important safety rule: never look at the Sun through binoculars or a telescope.
| Tool | What it does |
|---|---|
| eyes | see bright stars as dots |
| binoculars | gather more light |
| optical telescope | shows faint, faraway stars |
| radio telescope | collects radio waves |
| space telescope | looks from above the air |
Binocular log (a grown-up helps). On a clear night, count the stars you can see in a small patch of sky, such as the space between your two hands held at arm’s length. Then look at the same patch with binoculars (never at the Sun, and never in daytime pointing near the Sun). Count again and compare. If you do not have binoculars, draw a table of tools and what each could show you.
| Tool | Stars counted |
|---|---|
| eyes | 15 |
| binoculars | 90 |