Measurement

How do we find asteroids?

Distances to objects in space are very, very large. The nearest star (excluding the Sun), Alpha Centauri, is 41.23 trillion km, or 41,320,000,000,000 km!!

Galaxies are collections of millions, or billions of stars. The Milky Way is the galaxy in which we live, orbiting around it’s centre in a distant spiral arm.

Have you ever wondered how big a galaxy is? They contain millions to billions of stars but what does that really mean for size?

Reading about sizes in a book is one thing, but what if you could make an observation of a galaxy and then measure its size?

Have you ever wondered how big each of the planets is? Bigger or smaller than the Earth?

From our viewpoint on Earth, we are the centre of a huge sphere in space. And all the objects in the night sky appear as points on the sphere.