A sensory journey across the cosmos
Close your eyes for a second. Now imagine you could smell the universe.
Not the smell of earth after rain. (Its called PETRICHOR, btw).
Not your morning coffee. The actual universe.
When Neil Armstrong and Buzz Aldrin returned from their historic Moonwalk, they noticed an unusual odour in the Lunar Module.
A smell they described as burnt charcoal or ash. That’s the smell of the Moon. A first-hand cosmic experience.
But do you know what Mars smells like? Or the center of our Galaxy?
Let’s travel across the universe and find out what some popular places in the Universe smell like.
Or watch the video below to skip the post:
Location 1 – Mars
You’ve landed on the Red Planet. Take a breath.
The first thing that hits you is a sharp, metallic tang, like a freshly struck match or a handful of copper coins held up to your nose.
Then underneath it, a faint sulphuric punch. The unmistakable whiff of rotten eggs.
The Smell
Freshly struck match + copper coins + a whiff of rotten eggs.
The Chemistry
Mars gets its red-orange colour from iron oxide (OR rust). And rust carries a very real, very distinctive metallic smell.
Scientists have also detected traces of hydrogen sulfide (H₂S) in the Martian atmosphere, the same compound responsible for the rotten egg odour.
Perhaps, we’ll get to verify this first-hand when Martian regolith samples finally arrive on Earth.
Location 2 – Jupiter & Saturn
Jupiter and Saturn aren’t planets you land on since they have no solid surface.
Instead, you descend through layers of atmosphere, each one smelling progressively worse.
The Smell
Cleaning products and cat urine at the top.
Choking rotten eggs as you go deeper.
A cosmic pastry with catastrophic flavours.
The Chemistry
Start at the top. The upper atmosphere is rich in ammonia, giving that eye-watering cleaning chemical or cat-urine stench. Think of a neglected public bathroom multiplied by a million.
The deeper layer contains hydrogen sulphide (H2S) in the ammonium hydrosulphide (NH4HS) clouds. The deeper you go, the stronger and more suffocating it gets.
Titan, the Saturnian Moon
Titan is Saturn’s largest moon and one of the strangest places in the solar system.
It has a thick atmosphere, 2.5 times denser than Earth’s.
It has rivers, lakes, and oceans. It even has rain.
But here’s the twist: none of that is water. All of it is liquid methane and ethane.
The Smell
A petrol station on a busy highway. Overwhelmingly petroleum like smell, with a sickly sweet undertone.
The Chemistry
While Titan’s two main ingredients, Nitrogen and Methane are odourless, the hydrocarbon haze THOLIN that envelopes it gives it a complex, oily, slightly sweet chemical odour.
In addition, benzene falls from the sky as snowflakes. Benzene has a distinctive sickly sweet smell, found in gasoline and solvents.
So Titan, the most Earth-like object in the solar system, smells exactly like a petrol station.
Orion Nebula, a Cosmic Factory
The Orion Nebula (Messier 42) is one of the most studied stellar nurseries in the universe.
It sits just 1,350 light-years from Earth, visible to the naked eye on a clear night as a fuzzy smudge in Orion’s sword.
Inside it, stars are being born right now.
The Smell
Industrial creation, hot metal, exhaust, chemistry, and the faint electric charge of new energy crackling in the void.
The Chemistry
The Orion Nebula is packed with over 50 detected molecular species.
The most prominent smell-carriers are Polycyclic Aromatic Hydrocarbons (PAHs), the same molecules found in car exhaust, burned toast, and barbecue smoke.
Add ammonia for a sharp industrial cleaner note, plus ozone, that crisp, electrical smell you notice just before a thunderstorm.
This is what birth looks like at a cosmic scale.
Sagittarius B2 — The Cosmic Cocktail
Sagittarius B2 is a vast molecular cloud near the centre of the Milky Way, about 26,000 light-years from Earth.
It is one of the most chemically complex regions of the galaxy. And it contains enough alcohol to fill 400 septillion (4*10^26) pints.
The Smell
Raspberries and rum. Then a creeping chemical undertone of something deeply wrong: rotten eggs and bitter almonds.
A death cocktail served on a cosmic scale.
The Chemistry
In 2009, astronomers detected ethyl formate inside Sagittarius B2, the molecule that gives raspberries their distinct flavour and contributes to the smell of rum.
The cloud contains so much alcohol that each person on Earth could have 300,000 pints every day for a billion years.
But it also contains butyronitrile (described as suffocating), hydrogen sulfide, and hydrogen cyanide, carrying rotten egg and bitter almond notes.
The full experience: first hit of raspberries and warm rum, then the creeping, chemical undertone of something deeply wrong.
Red Giant Stars
A red giant is what our Sun will become in about 5 billion years, potentially engulfing Mercury, Venus, and maybe even Earth.
When a star exhausts the hydrogen in its core, it begins to expand to hundreds of times its original size.
The Smell
Thick and lingering like soot, ash, and something slowly smouldering.
The heavy scent of carbon hanging in the air, with a faint steamy mineral note.
The Chemistry
Many red giants have carbon-rich atmospheres, where carbon monoxide and long carbon chains dominate.
These stars actually produce graphite-like dust in their outer layers, contributing that sooty smell.
Others are oxygen-rich, ejecting water vapour through powerful stellar winds, adding a subtle, steamy character, like pouring water on hot iron.
Black Holes
A black hole itself has no smell. It is a region of space where gravity is so extreme that nothing, not even light — can escape, let alone scent molecules.
But the space around a black hole? That is a very different story.
The Smell
A sharp, metallic ozone tang.
The electric sensation of standing near a high-voltage arc, multiplied by a billion.
The Chemistry
Most black holes are surrounded by an accretion disk, a swirling ring of gas and dust being pulled inward at enormous speeds.
The gas in this disk is entirely ionized, stripped of electrons, existing as raw plasma.
There are no intact molecules here.
Rather than complex aromas, you’re left with the raw scent of super-heated particles reacting with surrounding space.
Quick Science: How Do We Even Know?
How do scientists know what something smells like in space without ever being there?
The answer is chemistry.
Every molecule has a unique pattern in the light it absorbs, characteristic dark or missing lines called an absorption spectrum.
Using telescopes that analyze absorption across different wavelengths, scientists can detect exactly which molecules are present in stellar objects.
And here on Earth, we already know what those molecules smell like.
So astronomers can say, with real scientific confidence why Sagittarius B2 smells like raspberries and rum.
So which cosmic location would you want to smell first, the raspberry rum cloud of Sagittarius B2, or the metallic tang of Mars?
Tell us your favourite in the comments below.
And check our other post on ‘6 Facts You Didn’t Know About the First Moon Landing’