Visible Light

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Visible Light

Most of the stuff scientists know about the universe comes from detecting waves from objects in space. Some objects like stars are huge, very hot, and very far away from us.

They give out lots of visible light - which is why you can see them, even though they're very far away.

We can see the planets in our Solar System because they reflect sunlight.

Early astronomers made observations of the universe just using the naked eye. Many very important discoveries of stars, comets and planets were made this way. Most astronomical objects are so far away and look so small that naked eye observations are only really useful for mapping their positions.

Telescopes magnify images, so distant objects can be seen in more detail. You can also see objects that are at larger distances. Many new objects have been discovered using telescopes and they've helped us learn more about what the universe is made up of. Telescopes on Earth have problems though. Space telescopes overcome these issues, but they're expensive.

Photographs of the universe can be taken using telescopes - this allows you to 'zoom in' and look at objects in more detail. It makes it easier to monitor an object by taking pictures of it at different times to compare them, and to share your observations with others. You can also see faint objects by allowing a long exposure time so you collect more light - which obviously can't be done done with just the naked eye.