9 Planets

Around 12 billion years ago, the universe was created from a massive explosion. The hot hydrogen and helium rapidly expanded and formed organized structures. After a few billion years, numerous galaxies formed, with each containing billions of stars. One galaxy, about 5 billion years ago, had a star called the sun, which attracted gas and dust to form nine planets, including Earth. About 12 billion years ago, scientists think, from a singular explosion, the universe was born. In those first moments, intensely hot hydrogen and helium raced outward, thinning, cooling, and clumping into vast, organized structures. Within a few billion years, countless galaxies had emerged, each one containing hundreds of billions of stars, constantly changing in cycles of birth, death, and rebirth. And one of those galaxies, about 5 billion years ago, one average-sized star, our sun, captured in its gravitational field the gas and dust that would become nine planets.