Well, early Earth had a newborn smell of its own… and it definitely wasn’t a sweet baby scent. Rather, advanced imagining techniques from scientists have brought us some interesting news about early Earth’s, uh… stench.
How much do you enjoy the smell of rotten eggs?
Because if you’d happened to have lived 1.9 billion years ago, you would have loved it. You’d have had no choice!
Scientists studied fossils taken from rocks around Lake Superior, Canada, and discovered bacteria that used to eat the outer shells of a larger type of bacterium called Gunflintia. In order to digest the hard shell, the happily dining bacteria needed to use oxygen atoms from salt found in seawater—perhaps better known by the term “sulphates.”
This process created gaseous carbon dioxide and released it into the atmosphere, along with the byproduct of—you guessed it—hydrogen sulfide. And that delicious byproduct is what creates the commonly known “rotten egg smell,” which anyone who lives near a water treatment plant in the modern age is highly familiar with.
Now, apparently this didn’t mean that the whole world stunk, but anyone with a delicate sense of smell would have certainly noticed the distinctive aroma.
Another interesting fact about the discovery is that it revealed the earliest known fossil record of “one kind of creature eating another creature,” says Martin Brasier, a paleobiologist at London’s Oxford University. "This is the group that was producing the oxygen we now breathe."