12: What does outer space smell like? (You're not gonna like it.)

What does the moon smell like? Do planets, comets, asteroids and space have their own odors?  The smells of the universe are not universal. Different objects in space — comets, planets, moons and gas clouds — all have their own distinctive aroma.  

Twelve people have walked on the Moon and all of them agree: the Moon smells like gunpowder.  

According to Space.com, astronaut Jack Schmitt said: “All I can say is that everyone's instant impression of the smell was that of spent gunpowder, not that it was 'metallic' or 'acrid'. Spent gunpowder smell probably was much more implanted in our memories than other comparable odors.”  

The Earth has a variety of smells, depending on what environment you're in. But what about the other planets in our solar system? Venus has a crushing carbon dioxide atmosphere, while Jupiter's atmosphere is stormy and turbulent. While we can see what color and understand the conditions on these planets, what do they actually smell like? Scientists hadn’t found clear evidence of the planet’s chemical composition until now.  

Yes, it has been confirmed that Uranus smells like... farts. Astronomers recently found that the atmosphere of Uranus has high levels of hydrogen sulphide, a compound that smells like rotten eggs. Mercury has a very sparse atmosphere and so would not have much of a smell at all. Venus and Mars, much like Uranus, have substantial quantities of eggy hydrogen sulphide.  

For Jupiter, the smell would depend on where you were in the atmosphere. Some regions have high concentrations of ammonia, hydrogen sulphide and others hydrogen cyanide (bitter almonds). Saturn and Neptune probably don’t have much of a smell because they’re composed chiefly of the odorless gases hydrogen and helium.  

Let's find out why.