What Makes Uranus The Coldest Planet In The Solar System?

Uranus, not Neptune, is the coldest planet in the Solar System.

Facts About Uranus

With reference to the Sun, Uranus is the seventh planet in the Solar System. It is located between Saturn and Neptune; and has an axial tilt of 98°. Uranus was the first planet to be discovered by scientists with the aid of a telescope. In the past, its slow orbit and dimness to the naked eye made it difficult to recognize it as a planet. Uranus has 13 rings and an equatorial diameter of 51,118 km. It takes 84 years to go round the sun. This duration is more than the life expectancy of humans in most countries. The mass of Uranus is approximately 15 times that of the earth. Astronomers claim that Pluto is a dwarf planet hence not a ‘real planet.’

The Temperatures Of Uranus

The temperatures of planets range from hot to cold depending on their distances from the sun. Using this principle, one will quickly conclude that Pluto is the coldest planet since it is located farthest from the sun. Pluto’s temperatures sometimes fall to levels as low as -387°F. Such low temperatures lead to the conclusion that Pluto is the coldest planet. However, since the planet is sometimes referred to as a dwarf planet, it is not included among the other planets.

Neptune is 2.8 billion miles away from the sun whereas Uranus is 1.79 billion miles away from the sun. It only receives 40% of solar radiation compared to the radiation that Uranus receives. In fact, Neptune is more than 1 billion miles away from Uranus. As such, Neptune should be the coldest planet in the Solar System. However, this is not the case because scientists have proven that Uranus occasionally reaches very low temperatures. The low temperatures are such as have never been attained by Neptune. Nevertheless, the average temperature of Neptune is far much lower than that of the seventh planet from the sun. Neptune has an average temperature of about -350°F while Uranus’ average temperature is -325°F. The coldest temperature ever recorded of a planet was -371°F and this was from Uranus. This means it reaches very low temperatures during certain occasions. The temperatures of Uranus are unmatched by any other planet.

Theories On The Coldest Planet

There are many theories that try to explain why Uranus achieves such low temperatures. It has been difficult to arrive at conclusions since using the distance as a reason for the cold temperatures is negated by the distance between the Neptune and Uranus. The angles at which Uranus receives solar radiation should also render it a warmer planet than Neptune. Some scientists think that the odd variation could be due to the structural components of Uranus which may affect the rate at which it retains solar heat. Others have suggested that there is a high likelihood of the planet experiencing such a strange temperature variation due to its unique orbit. It is believed that Uranus exhibits an orbit with a tilt like no other planet. The tilt makes the planet spill out a lot of heat into the space thus retaining very little. Consequently it becomes colder than the other planets.


More research is ongoing to determine the reason for the extremely cold temperatures found in Uranus. It must however be noted that Neptune can also be described as the coldest planet basing one’s argument on the average temperatures.

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