Uranus

Uranus is an ice giant, composed mostly of icy materials such as water, ammonia, and methane. Methane gives it its pale blue-green color. However, Uranus’s most unusual feature is its 98-degree axial tilt. It essentially rolls around the Sun on its side.

This extreme tilt causes bizarre seasons. Each pole gets 42 years of continuous sunlight, followed by 42 years of darkness as Uranus completes its 84-year orbit.

Uranus has a faint ring system and at least 27 known moons, many named after characters from Shakespearean plays. Temperatures on Uranus can drop as low as –224°C (–371°F), making it the coldest planet in the Solar System.

Scientists believe Uranus may have experienced a catastrophic collision with a large object early in its formation, knocking it onto its side and drastically altering its rotation.