Chapter 1
The hydrogen countdown
Chapter 2
The red giant expansion
Chapter 3
The planetary nebula phase
Chapter 4
The white dwarf retirement
YOUR GOAL
Master of The future of our Sun
Ch 1 · The hydrogen countdown
artiteacher The hydrogen countdown
Earth-sized star, Earth-sized star, we'll shrink right down when the hydrogen's gone!

artiteacher In about five billion years, the Sun's core will run out of hydrogen fuel.

BETA
artiteacher Swipe away the Sun's outer layers to learn how it shrinks into a white dwarf.
Fun Fact
Solar weight loss: The Sun loses about 4 million tons of mass every second just by shining.
Glossary
main sequence (noun)
The longest stage of a star's existence during which it continuously fuses hydrogen into helium. The Sun is halfway through this ten-billion-year phase, leaving five billion years of core hydrogen fuel.
The longest stage of a star's existence during which it continuously fuses hydrogen into helium. The Sun is halfway through this ten-billion-year phase, leaving five billion years of core hydrogen fuel.

