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Observing space

Observing the night skyObserving the night sky From Earth, we can observe with the naked eye other objects in space: our nearest neighbour, the Moon; our local star, the Sun; the other planets of the Solar System; comets and meteors; more distant stars and nebulae and even other galaxies. More can be seen through binoculars or simple telescopes, but to study in detail these objects or other objects that lie millions, or even billions, of light years away, powerful telescopes must be used.

The Milky Way as seen from EarthThe Milky Way as seen from Earth

The night sky

A clear, windless night is the best time to observe space from Earth. On many nights, the Moon is the brightest and largest object in the night sky. Up to 10,000 stars may be visible to the naked eye. All of them belong to the Milky Way Galaxy. From Earth, our view of one of the Galaxy’s spiral arms looks like a misty band across the sky. This is the “milky way” from which the Galaxy takes its name. Up to five planets (Mercury, Venus, Mars, Jupiter and Saturn) can also be spotted. You might also catch sight of a comet. Shooting stars are streaks of light that last usually for less than a second. They are tiny rock fragments, called meteors, burning up high above Earth.


The Hubble Space Telescope is so powerful it could detect light from a tiny torch 400,000 kilometres (250,000 miles) away.

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