S Chandrasekhar: The science prodigy who predicted how our sun was formed, and will eventually die

When you look up at the sky – at the night's stars, or the day's sun – you can give a little thanks to Subrahmanyan Chandrasekhar. He helped us find where they came from, and told us where they'll go.

Today's Google Doodle is commemorating a man that did probably more than anyone else to tell us about the mysteries of the night sky.

Mr Chandrasekhar became famous for his discoveries about the evolution of the stars. His work was vast, and he began early, developing his theory of stars' evolution before he had even turned 20.

That was a stunning discovery in itself. But it and the rest of the work he would go on to do tells us about some of the things that we see all the time – the stars that light up the night sky, and the sun that gives the Earth its energy.

But perhaps most interesting of all is Mr Chandrasekhar's work on how those stars will come to an end. He found that some large stars undergo a strange, spectacular death – one that sees them collapse, explode and then disappear.

Our sun, and our solar system that depends on it, doesn't have that to look forward to. It will end up losing energy and sucking up inside its own gravity, forming into a white dwarf – when that happens, it will crush down into a much smaller, far more dense thing.

Such white dwarfs keep their mass. But they shrink down to the size of our own Earth, making them incredibly dense.

That's the fate that awaits more than 97 per cent of the stars in the Milky Way.

But one of Mr Chandrasekhar's biggest discoveries was that bigger stars have something else waiting. He found that they will not shrink down but instead keep collapsing, blowing off their outer envelope in a huge explosion and eventually falling in on itself to create a neutron star. That neutron star can keep collapsing and eventually become a black hole.

All of that work helped shed light on some of the darkest and most mysterious parts of our universe: black holes and neutron stars.

It was two neutron stars that smashed into each other 138 million light years ago, in a discovery revealed this week that helped shed light on the beginnings of our universe. And without Mr Chandrasekhar's discoveries, we wouldn't know just how those strange, dense, heavy and small objects would come about.

Mr Chandrasekhar's 107th birthday is commemorated in a Google Doodle, which shows him measuring the stars. And that's just one of the many things he did – as well as working out what happens to objects like our sun in their twilight years, he contributed wide understanding to how they form and evolve over time.

It's his most famous work, the Chandrasekhar Limit that is specifically memorialised in the Doodle. That refers to his calculation that once a star reaches 1.44 times the size of our own sun, it doesn't form a white dwarf as expected but collapses, eventually becoming a black hole.

The discoveries on the Chandrasekhar Limit tell some of the story of the Nobel-winning scientists' life. Much of the work was done as he travelled from India to Britain, intent on working at Cambridge – and it was from there that he would move to the University of Chicago, where he worked for much of his life.

His work is more immediately useful, too, however – he doesn't just tell us how stars will die out but what we can do before they do. Much of his work helped inform today's space research and exploration, for instance.

And he was careful that his work would go on to help other scientists. He wrote a readable and condensed version of Isaac Newton's important Principia for common readers, for instance – and after his death, his Nobel Prize money was given away to support promising astrophysicists at the University of Chicago.