Spotting alien life – how ‘microfossils’ could fool scientists

Earth’s oldest fossils may be billions of years old – although such claims are highly controversial. These kinds of discoveries usually start with finding what appear to be preserved outlines of microscopic lifeforms that look similar to microbe fossils found in much younger rocks. The rewards for exploring truly ancient life are high, because as well as providing a glimpse at some of the earliest life on Earth, these microfossils can also act as a model for what evidence we might find for life on other planets such as Mars.