Diagram comparing the Sun with Stephenson 2-18. The latter is the current contender for the largest known star, a red hypergiant some 2150 times the diameter of the Sun. The Sun can fit into it 10 billion times!...

Artwork showing the Earth now (right) compared to how it might have looked around 2.4 billion years ago, before the great oxygenation event. The continents back there bear no resemblance to their modern counterparts; the atmosphere would have been th...