NASA Detected Evidence Suggesting Dwarf Planet Ceres Potentially Hosted Life in the Past
In the vast expanse of the asteroid belt, nestled between Mars and Jupiter, lies the dwarf planet Ceres. A recent study led by Francesco C. M. Carrozzo and a team of planetary scientists, geophysicists, and geochemists has revealed intriguing insights about Ceres' past, suggesting it could have been a habitable world.
The Dawn mission, which explored Ceres between 2015 and 2018, revealed evidence of an ancient briny reservoir beneath its icy shell. This reservoir, now a cold and salty slush due to the decay of radioactive isotopes, could have driven redox reactions, providing chemical energy to hypothetical microbes.
The most habitable period for Ceres was during metamorphism, between 0.5 and 2 billion years after its formation. During this time, the researchers believe that Ceres' core likely reached temperatures up to 800 Kelvin (around 527°C), high enough to trigger metamorphic reactions.
The Dawn mission also discovered carbon-based organic molecules on Ceres, further adding to the possibility of past habitability. The deep pore fluids on Ceres contain high concentrations of hydrogen and carbon dioxide, ideal for methanogenesis, a process that could have supported life.
A single kilogram of deep pore fluid on Ceres could potentially support up to 3 trillion microbial cells. However, the current temperatures on Ceres' surface, which swing between -93°C to -33°C with no atmosphere, make it inhospitable for known terrestrial life.
The National Academies' 2022 decadal survey recommended a mission to collect surface salts from Ceres under the theme "Origins, Worlds, and Life". A sample return mission could reveal isotopic fingerprints left by deep interior fluids, confirming whether energy-rich gases predicted in models actually reached the surface.
If Ceres was habitable in the past, many other icy bodies in the solar system, like moons of Uranus and some of Saturn's smaller satellites, may have also been habitable. The search for past habitability extends beyond big names like Europa or Enceladus, opening up new avenues for exploration and understanding the origins of life in our solar system.
Despite the bright white patches on Ceres' surface being not signs of life but salt, the dwarf planet continues to captivate scientists with its potential to reveal secrets about our cosmic neighbourhood and the possibilities of life beyond Earth.
