Stars: The Building Blocks of the Universe

Stars are massive balls of hot plasma powered by nuclear fusion, turning hydrogen into helium.
Our Sun is just one of about 200 billion stars in the Milky Way galaxy.
Stars come in many colors—blue stars burn hottest, while red stars are the coolest.
The largest stars can be more than 1,000 times wider than the Sun.
A star’s mass determines its entire life cycle, from birth to fiery death.
When stars die, they can explode in a brilliant supernova, scattering heavy elements across space.
Every atom of carbon, oxygen, and iron in your body was forged inside ancient stars.
Stars often form in clusters within giant clouds of gas and dust called nebulae.
Binary and multiple star systems—two or more stars orbiting each other—are common in the galaxy.
Neutron stars, the remnants of massive stars, are so dense that a teaspoon of their matter weighs billions of tons.