Analyse Observations

Over the past few hundred years, astronomers have discovered thousands of stars whose brightness goes up and down over time. These are known as variable stars. But what causes this to happen?

The ocean’s tides rise and fall every day, but have you ever wondered what causes them? The Moon and Sun both play a role in shaping the movement of water across the Earth. 

The Sun is a constant presence in our life on Earth. It gives us the heat and light we need to survive. But it is not a stable place. The Sun is a ball of hot plasma which is constantly changing.