
Space & Astronomy Wiki – the closest star to Earth –
Worshiped by every recorded human culture, the Sun – or Sol as the Romans called it – contains over 99.8 percent of the mass in the solar system, and is over a thousand times as massive.
Composed of 7.8 percent helium (He) and 92.1 percent hydrogen (H2) along with 0.1 percent oxygen and other elements, Sol looks solid in photographs, but its surface is a sea of hot 5,500 Celsius (10,000 degrees Fahrenheit) gas.
Called ‘Helios’ by the Greeks, the Sun is a stellar type G star called a main-sequence star but will change into a brighter, bigger and cooler red dwarf star around 5 billion years after its birth.
With a diameter over 100 times that of Earth at 1.4 million km (840,000 miles), the Sun is a common medium-sized yellow star you could fit over a million piles of earth inside.
Sitting at a distance of 149.6 million km (93 million miles) from our planet or 1 astronomical unit (AU), a distance which is used as a common measuring stick by astronomers viewing the solar system, the Sun transforms over 600 million tons of hydrogen into 596 tons of helium every second through nuclear fusion.
Dominating the gravity pool of the solar system, the mass of the Sun warps spacetime, which determines the orbits of the planets, and governs the movements of all mass bodies within the boundaries of the system.
For more information on the Sun go here.
Learn more about the connection between the Earth and Sun here.
To learn more about the Sun go here.
The Human Journey to the Beginning of Space and Time; Who are we?
Learn more about the search for habitable planets beyond Earth.
Learn more about the mysteries surrounding ultra-luminous X-ray sources.