Which planet is farthest from the Sun?

Neptune is the planet farthest from the Sun. It is the eighth planet in the Solar System, orbiting at an average distance of about 4.5 billion kilometres, or 30 astronomical units, from the Sun.

Neptune takes approximately 164.8 Earth years to complete one orbit. Because it is so distant and faint, it cannot be seen with the unaided eye. Its existence was predicted mathematically after astronomers noticed unexpected changes in Uranus's orbit.

Johann Galle first observed Neptune through a telescope on September 23, 1846, near the position predicted by Urbain Le Verrier. Neptune is an ice giant with a deep blue appearance, powerful winds, faint rings, and at least 16 known moons, including Triton.

Pluto is farther away on average, but it is classified as a dwarf planet rather than one of the Solar System's eight planets. Uranus is Neptune's neighbouring planet and is closer to the Sun.