A fossil is proof of a once-living thing from a past geological age. Studying the oldest fossils found on Earth helps the experts to get an idea about what alien life forms we may find on other planets, for example, Mars.
The question is, how can we tell the difference from a fossil and other non-organic geological characteristics? NASA scientists alleged back in 1996 that they uncovered resides of extraterrestrial life on a meteorite but was proved not to have biological origins after all.
Microfossils might not be evidence of alien life
Experts have conducted a recent study proving how some objects similar to microfossils can form without any actual microbes. This study may raise doubts about particular fossils, however, all bad to the greater good. In the end, experts will have enough evidence regarding the past geological age – on this planet or others.
It is hard to distinguish pseudofossils from real microfossils. At first glimpse, it can look like a microfossil of a billion-year-old microscopic life form. However, it may be just a speck of microbe-shaped dirt or something similar to a mineral that evolved in a crack in the rock.
As tricky as it is, geologists and astrobiologists look at the shape, structure, and chemical composition of samples. From there, they conduct experiments and compare these characteristics with alkaline lakes or from well-preserved uncontroversial examples from the older rock record.
Occasionally filaments of iron oxide have taken the shape of the organism, which encompasses some new highly-profile discovers, including those from 4-billion-year-old rocks in Canada.
The study proves that not all hollow tubular filaments made of iron oxide are biogenic microfossils.
Researcher Sean McMahon experimented “chemical gardening,” which eventually established complex arrangements of hollow tubular filaments that can superficially look like shapes of microbial lifeforms.
Real or not?
This study clearly shows that discovering fossils of alien life on Mars must be funded by remarkable evidence. McMahon admits in his published paper that the reported 4-billion-year-old iron oxide filaments could just a result of fluids chemically reacting with the ancient seafloor than Earth’s oldest fossil lifeforms.
But this investigation also doesn’t dismiss the possibility of authentic ancient iron oxide microfossils or their use as a model for evidence for life on other planets. These fundamental questions remain unanswered for now, but we are on a journey toward the truth.