Everyone and everything that has ever lived owes its existence to the Sun. It's the star of our solar system, controlling the weather and so much more. But the Sun remains a mystery in many ways, says Professor Lucie Green, a solar physicist and host of The Sky at Night BBC series.
Her first book, 15 Million Degrees: A Journey to the Centre of the Sun, sheds light on what we know about this important feature in our daily lives and what we might learn from the first Solar Orbiter mission to the Sun.
So what exactly is the Sun? It is a question that scientists have grappled with for hundreds if not thousands of years, Prof Green says.
“It’s incredibly large – you could fill over a million Earths inside it making the Sun is by far the biggest object in the solar system.”
Although the Sun has no solid surface, it's actually vast ball of very hot gas - 15 million degrees C at its core - and it contains over 99.9 percent of all the mass in the solar system.
The consequence of being so massive is that it generates power and light. Nuclear reactions happen in the centre of the Sun which allow it to ‘cannibalise’ itself as it turns its own material into the energy that we receive as sunlight and heat.