The Sun, Our Star

The Sun, our star, the source and sustainer of all life on Earth, is also a death star in the making. To know the Sun is an age-old dream of humankind. For centuries, astronomers contented themselves with analysing small sips of sunlight collected through specialised instruments. They chased after eclipses that exposed otherwise hidden layers of the Sun’s substance, and they launched Earth and Sun-orbiting observatories to monitor our star from space. Today, several satellites ‘watch’ our star from outer space. In August 2018, Nasa’s Parker Solar Probe set off on a mission to go so far as to ‘touch the sun’ for the first time.

Our view of the sun from here is relatively murky. Nevertheless, astronomers have managed to piece together an understanding of the stars, and especially the Sun itself - how it’s constructed, how it behaves, how it came to be, forming from a vast cloud of cold hydrogen gas and the dust of older stars in a sparsely populated region of the Milky Way.

Dava Sobel orbits the Sun, getting as close as she dares, to understand the immense relationship we have with our nearest star. She begins by piecing together what we know of the Sun, visiting the world’s most powerful solar observatory, Big Bear in California.

Music composed by Chris O'Shaughnessy
A Cast Iron Radio production for the BBC World Service

Audio for this programme was updated on 1st September 2020.

Image: Artist's impression of the Parker Solar Probe approaching the Sun (Credit: NASA/Johns Hopkins APL/Steve Gribben via European Photopress Agency)