Scientists searching for evidence of life beyond Earth have discovered organic material on Ceres, the dwarf planet located between Mars and Jupiter.
The carbon-based materials, similar to what may have been the building blocks for life on Earth, were discovered by NASA’s Dawn space probe.
The exact molecular compounds in the organics cannot be identified, but they match tar-like minerals such as kerite or asphaltite.
“The discovery indicates that the starting material in the solar system contained the essential elements, or the building blocks, for life,” said Dawn’s lead scientist, Christopher Russell.
“Ceres may have been able to take this process only so far. Perhaps to move further along the path took a larger body with more complex structure and dynamics (like Earth).”
Ceres, a Texas-sized rock-and-ice world about 590 miles (950 km) in diameter, is the largest object in the asteroid belt and is located about three times farther from the sun than Earth.
Its composition is thought to reflect the material present in parts of the solar system when it was forming some 4.5 billion years ago.
The organic material was found near a 31-mile-wide (50km) crater in Ceres’ northern hemisphere and experts say the location and type of organics mean they cannot have been deposited by a crashing asteroid or comet.
The dwarf planet now joins Mars and several ocean-bearing moons of Jupiter and Saturn, among others, as places of interest to scientists looking for life beyond Earth.
“This opens the possibility that primitive life could have developed on Ceres itself,” said planetary scientist Michael Kuppers of the European Space Astronomy Center.
But Mr Russell was less bold, saying: “I think these organic molecules are a long way from microbial life.
“However, this discovery tells us that we need to explore Ceres further.”