Often considered to be the most foul-smelling fruit in the world, durian gives off a smell like raw sewage, decaying flesh, or dirty gym socks. Image Credit: Pexels/Hong Son

Rotten eggs or animal puke, which smells worse?

Click start to play today’s Spell It, where you can create the word “stink”.

The most awful smells in the world actually come down to a complicated science. A 2007 study in the US-based Journal of Neuroscience, found that it all depends on the underlying molecular structure. Researchers analysed 1,500 properties of 150 different molecules, to find if there was a connection between an item’s pleasant smell and the way its molecules were arranged.

They noticed that molecular weight and electron density are closely associated with scent. Lighter, more compact molecules tend to be more pleasant, while molecules that are more spread out and heavier, are associated with bad smells. For instance, the heavy, dense molecule butanol smells like rotting wood, while the light, compact limonene smells like citrus.

Here are three awful smells, universally acknowledge to be the worst man has ever known:

1. Uranus

A team of astronomers found that the reason why the planet Uranus smells like rotten eggs, is because of hydrogen sulfide – a gas with a distinct smell that’s in abundance in the planet’s atmosphere.

2. Durian

This notorious fruit gives off such a potent smell, it once led to the evacuation of a university in Melbourne, Australia, because students feared there was a gas leak. The durian gets its impossible-to-ignore smell from 44-odour active compounds.

3. Rafflesia arnoldii

Appropriately named the ‘stinking corpse lily’, this plant smells exactly like a decaying corpse, with undertones of fish and sweaty socks to boot! It’s also the largest single flower in the world, and measures around one metre across. The corpse lily takes several months to blossom, and when it does, it releases its putrid odour, which can last for up to four or five days.

What is the stinkiest smell you’ve encountered? Play today’s Spell It and tell us at games@gulfnews.com.