A time lapse photo taken by the Hubble Space Telescope of Uranus showing the movement of its mysterious auroras. Another little known fact about Uranus is that it has a ring. - pix by ESA/Hubble & NASA, L. Lamy/Observatoire de Paris (CC BY 2.0)
URANUS has been the butt of many a schoolkid's joke during science class, thanks to its rather "quirky" yet misunderstood name, more or less since its discovery in 1781 by William Herschel.
He actually wanted to call his newly discovered ice giant George, after the then King of England, George III, but settled on calling it Uranus after the Greek deity of the sky.
It's a coincidence that the name sounds like an impolite phrase in English, but maybe there's some truth to that.
Is it true that Uranus smells like farts?
Verdict:
TRUE
Uranus is primarily composed of hydrogen and helium, but it also contains a significant amount of methane.
Methane is a colourless, odourless gas that is found on Earth in natural gas deposits, wetlands, and in the digestive systems of animals, including cows and termites.
There is so much methane on Uranus that its blue-green colour is caused by the presence of the gas in its atmosphere.
The gas absorbs red light and reflects blue and green light.
In terms of odour, methane by itself does not have a strong odour. However, other gases in Uranus' atmosphere could contribute to the planet's smell.
According to a study published in the journal Nature in 2018, Uranus' atmosphere is rich in hydrogen sulfide.
The study, which was led by Patrick Irwin of the University of Oxford, analysed data from the Gemini Observatory in Hawaii and the Very Large Array in New Mexico to study the composition of Uranus' atmosphere. The researchers found that the upper atmosphere of Uranus is rich in hydrogen sulphide, which is produced by the interaction of sunlight and the planet's atmosphere.
The researchers noted that the concentration of hydrogen sulphide was lower than the concentration of methane, which is the primary component of the planet's atmosphere.
However, the odour of hydrogen sulphide is much stronger than the odour of methane, which means that the planet's odour is likely to be dominated by the smell of rotten eggs.
Hydrogen sulphide smells like rotten eggs because it actually is what gives spoiled eggs their unique odour.
"Sulphur bacteria" pass the gas as a by-product of them digesting the egg. These same bacteria (or at least their cousins) are also present in the human digestive tract and give human flatus its distinct, alarming qualities.
According to another study published in the Planetary Science Journal in 2021, researchers detected ammonia in the lower atmosphere of Uranus using data from the Atacama Large Millimeter/submillimeter Array (Alma) in Chile.
The researchers noted that the concentration of ammonia in Uranus' atmosphere is much lower than the concentration of methane or hydrogen sulphide, but it is still an important component of the planet's atmosphere, and there is enough of it there to impact its odour.
What does ammonia smell like? Well, seeing that urea is essentially just ammonia but with more parts, ammonia smells like sweat or urine.
So what would a person smell if they were instantly transported to Uranus? Well, they would more or less die immediately from breathing in toxic gases.
However, in those few short moments before death, our hapless astronaut would realise that Uranus smells like a noxious cocktail of urine and fart gas.
References:
3. https://science.nasa.gov/science-news/science-at-nasa/2006/11apr_george
