Why Does Uranus Smell Like Rotten Eggs?

By Antonia Čirjak on April 21 2020 in Answer

The clouds that can be found all over the upper layers of the atmosphere on Uranus are made up mostly of hydrogen sulfide.
  • The reason why Uranus smells like rotten eggs is that the clouds surrounding it are made up of hydrogen sulfide.
  • The reason why large amounts of hydrogen sulfide are present in the air on Uranus is because of its positioning in relation to the sun.
  • The atmosphere on Uranus is similar to that of Neptune but different to those on Jupiter and Saturn.

Yes, you have read the title of this article correctly.

Now that we have got your attention, it is time to explain why exactly an entire planet smells like something we throw in the garbage on Earth. The simplest answer to this question was given to us by a recent study.

The clouds that can be found all over the upper layers of the atmosphere on Uranus are made up mostly of hydrogen sulfide. This is the molecule that gives rotten eggs their awful stench, so it is easy to conclude why the planet smells that way.

The Atmosphere Of Uranus

According to scientists, just by descending through the clouds above Uranus, we would be bombarded with awful smell right away. However, that would be the least of our problems. Before we would even get the chance to notice the smell, we would suffocate due to the atmosphere that is made up mostly of helium, methane, and hydrogen. Another problem we would face is the freezing temperatures that go as far as negative 200 degrees Celsius.

The composition of the clouds above Uranus has been the subject of research for the longest time. It was hard to make observations because the planet is too distant, as opposed to Jupiter and Saturn. Those two planets were also visited by orbiter missions, making the data on them more abundant.

According to scientists, just by descending through the clouds above Uranus, we would be bombarded with awful smell right away.
According to scientists, just by descending through the clouds above Uranus, we would be bombarded with awful smell right away.

The biggest question researchers had to answer was whether the clouds of Uranus were made up of ammonia ice (like on Jupiter and Saturn) or hydrogen sulfide ice. By carefully examining the air around Uranus using a specially designed spectrometer, scientists were able to get their answer, which was that hydrogen sulfide makes up the atmosphere of Uranus. 

Hydrogen Sulfide And Ammonia Are To Blame

A big problem when trying to find what exactly makes up the atmosphere around the planet is that only the parts above the clouds can be accurately observed. In those parts, hydrogen sulfide and ammonia are present in much smaller amounts, so it was no easy task to find out the components of the atmosphere of Uranus. But, thanks to the hard work of many researchers, we now know that the planet smells like rotten eggs, meaning it was all worth it. 

Jokes aside, this is a great accomplishment for astronomy and helps us understand the workings of other planets. This might bring us to further discovery, maybe even the one we are all searching for - is there life on other planets? This discovery also means that we can conclude that Uranus has similar clouds to the ones on Neptune. They differ from the clouds of Jupiter and Saturn because they are much farther from the sun than those two. 

This positioning is also the reason for the large amounts of hydrogen sulfide in the atmosphere of Uranus. The balance between sulfur and nitrogen is determined by the location and temperature during the formation of the planet. The fact that Uranus is far from the sun also keeps its temperature extremely cold. It is an interesting thing, the fact that something that happened millions of years ago determined how a planet would smell. Science sure does teach us a lot of interesting things!

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