The ocean floor is home to a staggering 2.9×1029 single-celled organisms — that’s 10 million trillion microbes for every human on the planet — but vast though it is, this figure is only 8% of the previous estimate of 35.5×1029.

A cluster of Escherichia coli Bacteria magnified 10,000 times.

Read more at Nature “New estimate reduces the number of microbes on Earth by around half”