Northern Ireland Key Stage 4

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?

Use our simulator to investigate the effect of gravity on other worlds. Then use your measurements and a bit of maths to calculate the strength of gravity in each location across the Solar System!

An exoplanet is a planet which orbits a star that is not our Sun. The first exoplanet was discovered in 1992. It was found in orbit around the pulsar PSR 1257+12.