The largest mountain in our solar system is on Mars. The volcanic mountain known as Olympus Mons on planet Mars reaches a towering 16 miles (26 kilometers) high and spreads to 341 miles (550 kilometers) at its base. Mars does not have tectonic plate movement on the planet’s surface like Earth does. This means the magma hotspot underneath Olympus Mons remains fixed, allowing for repeated lava flows that have built on top of each other over time.
Mountain ranges are long chains or groups of mountains, such as the Rocky Mountains or Himalayan Mountains. Ranges are usually 1,000 or more miles long.
The world's tallest mountain ranges form when pieces of Earth's crust—called plates—smash against each other in a process called plate tectonics, and buckle up like the hood of a car in a head-on collision. The Himalaya in Asia formed from one such massive wreck that started about 55 million years ago. Thirty of the world’s highest mountains are in the Himalaya. The summit of Mount Everest, at 29,035 feet (8,850 meters), is the highest point on Earth.