What is the Sun?

What Can We See on the Sun?

Close up images of the Sun including solar flares, sunspots, and a solar eclipse

What is Gravity?

Planet Earth in space. Three children are standing on the planet. Arrows show the pull of gravity from where they are on the surface into the centre of the Earth.

Big Bang

The evolution of the Universe.
Credit: NASA

The Big Bang is the explanation for how the Universe started. Astronomers think that everything started in a single point. Then everything expanded and stretched to grow into the huge Universe we see today.