The Milky Way Galaxy, home to our solar system. It’s believed our solar system formed at least 4.5 billion years ago, when a huge cloud of dust and gas collapsed into a dense mass. That mass began to spin and flatten into a disk. That disk grew hotter and hotter until finally a new star, our sun, was born. Leftover dust and gases continued to whirl around the sun and over millions of years formed the planets and moons that make up our solar system.
The sun is at the center, it’s gravity binds the solar system together. It accounts for 99% of the solar system’s mass.
The closest planet to the sun is Mercury, a relatively small planet known for it’s extremes of temperatures. Above 800ºF during the day and minus 300ºF at night.
Next is Venus, the near twin of the Earth in size, mass and density. It’s atmosphere is mostly carbon dioxide, a greenhouse gas that traps the sun’s heat and raises the surface temperature to nearly 900ºF. Clouds of sulfuric acid swirl above Venus’ rocky surface.
The third planet is Earth, an active planet that’s constantly changing. More than 70% of its surface is covered by water. Earth teems with life - something that, so far, has been found nowhere else.
Just beyond Earth lies Mars, a barren planet with striking geographic features, including red soil, canyons four times deeper than the Grand Canyon, and polar ice.
Between Mars and the next planet is the Asteroid Belt -millions of rocky fragments, most no more than a mile across.
The fifth planet from the sun is far and away the largest: Jupiter - a gaseous giant big enough to hold more than 1,300 Earths. It’s great red spot alone, a huge hurricane-like storm, is twice as wide as Earth.
Saturn, the second largest planet, is next. Famous for its massive rings of ice and ice-covered particles.
Seventh from the sun is Uranus, which is unique because it rotates on its side. It too has rings, and at least 27 moons.
Neptune, the eight planet, is perhaps the windiest planet in the solar system. With gusts over 12,000 miles per hour. Neptune marks the end of the planets, but not the end of the solar system.
Farther on is Pluto, a dwarf planet. At its greatest distance, Pluto orbits more than 4.5 billion miles from the sun.
As vast and diverse as our solar system is, its but one in a galaxy of billions of stars, in a universe comprised of billions of galaxies.