This is How Cold The Surface of Uranus Really is, And What Could Survive There

The seventh planet from the Sun, Uranus, bears the name of the Greek god of the sky. It is the third-largest in diameter and the fourth-largest in terms of mass. The planet is an ice giant due to its bulk chemical composition. It is not a gas planet like Jupiter and Saturn.

The planet is known for its sideways rotation axis. This results in Uranus’ north and south poles being located where one would usually find a planet’s equator.

Uranus is home to the extremes. The most powerful winds here can reach speeds of up to 560 mph. The same applies to temperatures – as you’ll see soon enough, they go extremely low!

Without any further ado, let’s see how cold the surface of the planet really is and, most importantly, what could survive there!

How cold is the surface of Uranus really?

The average temperature of Uranus’ surface is about -353 °F. It is worth taking into account that the planet doesn’t have a solid surface and consists mainly of clouds made of ice crystals. Within these clouds, the average temperature is -315 °F. Things don’t get any warmer in the planet’s lower atmosphere. The coldest temperature recorded there is -371 °F.

The cold weather is attributed to the planet’s mass, consisting primarily of icy materials such as ammonia, methane, and water.

Interestingly enough, the planet remains extremely cold even if one of the poles receives direct sunlight for about 42 years. What’s crazier is the fact that, while under constant sunlight, the pole will still be colder than the planet’s equatorial region. While this phenomenon causes significant seasonal variations, Uranus stays cool. The planet’s core is believed to be cold, with no heat source, while certain research points to a decently heated core of up to 9,000 °F.

According to NASA, the mean temperature of Uranus is -320 °F (for this planet, the mean temperature was recorded at an atmospheric pressure level equal to Earth’s pressure at sea level).

What could survive on Uranus?

A study shows that single-celled organisms can live and grow normally at temperatures above approximately -4 °F. Once temperatures drop below this value, most organisms undergo the process of vitrification, which means they adopt a glass-like state, and their life cycle is halted entirely. 

Some organisms, called cryophiles, can survive at low temperatures. Still, these are believed to undergo vitrification once temperatures drop under -13 °F. Given that Uranus has an average surface temperature of -353 °F, no organism could actually survive there. It would be stuck in a continuous glass-like state, with no opportunity to develop or evolve.

In short, anything introduced to the planet’s surface in a cryogenic state (any frozen organism above absolute zero, -459.67 °F) would survive there, without growing or developing, until reintroduced in an atmosphere or location with optimal living temperatures.

The problem is that Uranus still has gravity – about 89% that of Earth. The bigger problem is that the planet’s core can be as hot as 9,000 °F, and the rest of the planet is gaseous and icy. Any frozen organisms introduced to the planet’s surface would either be swept by the 560 mph powerful winds or fall rapidly towards the planet’s core.

Could tomato plants or other vegetables/fruits survive on the surface of Uranus?

Tomatoes, other vegetables, and fruits couldn’t survive the freezing cold surface of Uranus. For most plants, the maximum temperature they can endure is about 90 °F, while the lowest is associated with some frost, but not freezing.

Given that Uranus’ surface temperature is -353 °F, it is clear that no plants could survive there. After all, don’t forget that this planet is known for being an ice giant. Some plants might go well with chilly temperatures, but not with temperatures this close to absolute zero.

Could tardigrades survive on the surface of Uranus?

Tardigrades are the most resilient animals on our planet, as they can survive extreme conditions. For example, they survived being exposed to outer space, and most scientists believe they could even survive the apocalypse. But could they live on the surface of Uranus?

The comfortable temperatures for tardigrades are those above freezing and up to 98 °F. This is called their active state, where they grow and develop normally. However, they rely on their tun state when exposed to extreme conditions. This is characterized by a dried and lifeless appearance, much like hibernation. In their tun state, tardigrades can survive at temperatures as low as -328 °F and as high as 300 °F.

Given the temperatures on the surface of Uranus, tardigrades couldn’t survive this planet. The temperature is simply too low for their tun state to be preserved. On top of that, this state can’t be associated with living, as the organism can’t develop/grow.

Would water be frozen or liquid on the surface of Uranus?

Water would be rock-solid frozen on the surface of Uranus. At -353 °F, water molecules would be so dense that the formed ice would be as tough as rock. After all, frozen water can’t get more frozen – it can, however, get tougher and more resilient to external factors.

Even though water freezes at 32 °F, scientists are actively trying to keep it liquid for longer and at lower temperatures. They’ve been able to keep it in a liquid state at temperatures as low as -49 °F, which translates to various applications in the future. For example, this means that astronauts or explorers could preserve water in extremely cold environments.

Are there any signs of life on Uranus?

Uranus has never shown any signs, past or present, of life. The planet is home to extreme conditions and environments. The temperature, pressure, and surrounding materials are in extreme states that cannot possibly support life.

The main factors are the immense pressure and the planet’s strong winds – we’ve already mentioned temperatures.

The main characteristics of Uranus

How long is a one-way trip to Uranus?

A one-way trip to Uranus (from Earth) is about 8.5 years long. This value takes into account the trip made by Voyager 2 sent by NASA to Uranus back in the 70s-80s. Modern spacecraft are likely able to complete the trip faster, but it is not guaranteed.

At the same time, it is unlikely that another spacecraft will be sent to Uranus in the near future. Voyager 2 is the only spacecraft to have traveled there.

7 interesting facts about Uranus

Here are some other interesting facts about Uranus, one of the coldest planets in our Solar System:

• Uranus can be seen with the naked eye. The only things you know are a darker-than-usual night sky and the planet’s exact location.
• Uranus was the first planet discovered after the telescope had been invented. Recorded in 1690, the planet was initially considered a part of the Tauri constellation.
• Uranus has a total of 27 moons – most of them are small. Unlike traditional moons, it is believed that the bodies orbiting Uranus were created from an accretion disk that once surrounded this planet.
• Uranus has a ring system, just like Saturn. The main difference is that Uranus’ rings are incredibly dark and rather small (the biggest is a fraction of a meter). 
• The planet’s next summer solstice will take place in 2028. One year on Uranus’ northern side lasts 84 Earth years, so the last solstice occurred in 1944.
• Uranus is a planet that rolls through space. It has an inclination of 97 degrees to its orbit’s plane. It is believed that this was caused by a frozen object the size of Earth striking Uranus in the past.
• Uranus fights Neptune for the coldest planet in the Solar System title. This is why you might come across sources suggesting that Uranus is the coldest. However, this planet’s mean temperature is -320 °F, while Neptune has a mean temperature of -330 °F, based on NASA studies.

Up Next:

• This Is How Much You’d Weigh On Uranus
• This is How Cold The Surface of Neptune Really is, And What Could Survive There
• Which Planet is the Windiest, and Why?

The photo featured at the top of this post is © iStock.com/Ianm35