Our star, the Sun, defines almost all life on the planet. Even so, we take this nuclear fusion powerhouse in our cosmic backyard as an obvious steady presence in our day to day endeavours. Our year signifies one revolution of the Earth around the Sun. Our day signifies one rotation of the Earth on its own axis as it orbits the same star.

Our sleep-wake cycle, present in several animals, including humans, is governed by the circadian rhythm, which finds its basis in the increase and decrease in brightness from day to night. Photosynthetic organisms, entirely dependent on the Sun, form the basis of over 99 per cent of all ecosystems that we know of on Earth.

And yet, our Sun has a lifetime, just like any other star. It will one day run out of fuel too, and eventually ‘die’. The Sun, however, is too small to go supernova. Instead, our star will one day become a red giant star, extending in size so much that its surface will be where the Earth is in its present orbit today.

It will eventually lose its outer layers over the course of millions of years, leaving behind a white dwarf – the exposed core of the star. Don’t fret, however – the Sun will not become a red giant for another fivebillion years!