Uranus is the coldest planet in the Solar System. Some facts about space seem to defy simple logic. Neptune is the farthest planet from the Sun, so you might expect it to be the coldest planet. But it’s not: Uranus is. The question is, why is Uranus the coldest planet in the Solar System? Could Uranus’s plummeting temperature be related to the planet’s atmosphere? Did Uranus lose most of its primordial heat early in its life? Or could it be related to the planet’s strange tilt, relative to the rest of the planets that orbit our Sun?