This is the billion-dollar question that still remains unanswered today.
A few of the orange-colored carbonate
globules found in ALH84001. Credit: NASA
Will start this with another question:
In 1984 meteor hunters found a meteorite in Antarctica. Ten years later the scientists figured out that the meteor came from Mars. Then, they looked inside it.
What they found turned into being one of the biggest debates in astrobiology.
Is that fossil life they saw inside the meteorite ALH84001 or are the odd shaped worm like features just biomorphic features? What did it mean that the team detected organic molecules inside it and what made the magnetite grains found inside so pure when we know that here on Earth is that definitely a feature we see in biological systems?
These are only few questions in the quest of understanding life.