Analysis of data collected by the Mars Curiosity Rover revealed evidence of a past cataclysmic event that would have ended all life on the surface of the red planet. The event could have involved intense volcanic activity, or been the result of a massive collision with a meteor, asteroid or planet. Either way, this catastrophe ultimately demolished the Martian atmosphere.
When Planets Collide, Bad Things Happen
With the information provided by the Curiosity Rover, we now know that Mars possessed an atmosphere rich in oxygen about four billion years ago. The Curiosity also found proof that water saturates the Martian soil, and that at some time in the distant past liquid water flowed freely on the planet’s surface.
This all suggests that conditions on Mars billions of years ago would have been favourable for the development of life. Whether it possessed these conditions long enough for life to actually evolve remains uncertain. Since the solar system itself is estimated to be about 4.5 billion years old, the time frame would have been condensed and it’s possible that only simple life forms would have had time to appear.
What is known for sure is that approximately four billion years ago, something dramatic and catastrophic occurred that changed things on Mars forever. Scientists studying Curiosity data were able to deduce this through measurements of the existing Mars atmosphere, which revealed the presence of two different forms of the gas argon. One form was quite primitive and ancient, while the other was created more recently through radioactive decay.