Mars,
Pictures from Perseverance Rover.
The hunt for
red planet residents began close to four decades ago, when the agency sent two
spacecraft — the Viking landers — to Mars. Their task was to prove that the
planet, while red, is not dead.
The landers
initially sent back data that seemed consistent with bacteria-like organisms in
the soil. But with further analysis, early optimism soured. Was there life on
Mars?
NASA
concluded: Probably not.
This
wishy-washy answer was frustratingly ambiguous, especially for a $1 billion
experiment. So, NASA is now taking a different approach in its hunt for
microbes. Unlike the Viking landers, the new Perseverance rover isn’t looking
for chemical signs of metabolism. Instead, Perseverance will trundle around
Mars’ gaunt landscapes searching for sediments. These could contain clues to
organisms that pitched and swirled in long-vanished seas.