The Sun is the yellow dwarf star at the centre of our Solar System. It is a sphere of hot electrified glowing gases, powered by nuclear fusion reactions deep down in its core. The star radiates this energy out into interplanetary space. Our Sun and Earth connection drives the seasons, ocean currents, weather and climate but also creates dangerous radiation belts and beautiful aurorae. It is by far the most important source of energy for life on Earth and though it is special to us, there are billions of stars like our Sun scattered across the Milky Way galaxy.
The Sun is huge containing 99.86% of the mass of our entire solar system. Over 100 Earth-sized spheres could fit across the Sun’s diameter; so, compared to our SUN artwork, our planet would be roughly the size of a tennis ball.
Our Sun is about 150 million kilometres (93 million miles) away from Earth – it takes sunlight 8 minutes to travel from the star to us. When you glance up at the Sun, you are seeing what the star looked like 8 minutes ago.
The colossal pressures at the heart of the Sun create perfect conditions for thermonuclear fusion to take place. This solar core is the hottest part of the star at an immense 15 million degrees Celsius.
A total of 173,000 terawatts (trillions of watts) of solar energy reaches the Earth continuously, more than 10,000 times the world’s total energy use.
Our Sun has a strong magnetic field that looks similar to that found around a bar magnet. Every 11 years or so, this magnetic field flips completely. This means that the Sun's north and south magnetic poles switch places.
A solar wind composed of charged particles streams away from the Sun's surface and out through the solar system. As well as this, large solar storms can rocket out from the star and head towards the Earth, bombarding our planet’s magnetic field. We call this phenomena space weather.
Launcheed on February 2010, SDO is part of NASA's "Living With a Star" programme. The mission is designed to understand further our "Sun-Earth connection", particularly in regard to space weather impacting our planet.
Main NASA website about missions to our closest star and the science of the Sun.
Launched in February 2020, Solar Orbiter will help us understand how our star creates and effects the giant bubble of electrified gases (plasma) that surrounds the entire Solar System and influences the planets within it. It will do this by travelling closer to the Sun than Mercury, braving the fierce heat to provide a unique view of the Sun. Solar Orbiter will also journey outside the Sun-Earth plane, viewing our Sun’s polar regions for the first time.
Launched in 2018, Parker Solar Probe is a NASA spacecraft whose mission is to undertake unique observations of the outer corona of the Sun. It will fly through the Sun's atmosphere as close as 3.8 million miles above our solar surface, more than seven times closer than any spacecraft has been before; by comparison, the average distance of the Earth from the Sun is about 150 million km.
Educational website about the Sun, funded by the Science and Technology Facilities Council.
An STFC project that aims to ignite curiosity and develop creativity in school children using space science.