Astronomers have found that organic molecules on the dwarf planet Ceres originated there, rather than being delivered from elsewhere. This suggests Ceres has always had some of the key ingredients for life.
The research, led by Dr Simone Marchi from the Southwest Research Institute (SwRI), was presented yesterday at the American Astronomical Society’s 49th Division for Planetary Sciences Meeting in Provo, Utah.
The discovery of organics on Ceres was reported earlier this year, found near the Ernutet crater, located in the northern hemisphere of the dwarf planet. Using data from the Dawn spacecraft, which is currently in orbit around Ceres, Dr Marchi's team modeled how these organics may have been delivered to the dwarf planet.
“The discovery of a locally high concentration of organics close to the Ernutet crater poses an interesting conundrum,” Dr Marchi said in a statement.
“Was the organic material delivered to Ceres after its formation? Or was it synthesized and/or concentrated in a specific location on Ceres via internal processes? Both scenarios have shortfalls, so we may be missing a critical piece of the puzzle.”
Although labeled a dwarf planet, Ceres is perhaps better described as a planetesimal, the remains of material that led to the formation of planets. Located between Mars and Jupiter, it is thought to have formed about 4.5 billion years ago, the same time as the Solar System itself.
The researchers considered if a comet could have delivered Ceres' organics, or perhaps an asteroid. However, the distribution of organics suggests they have always been there.
“These findings indicate that the organics are likely to be native to Ceres,” Marchi said.
Finding organics are native to Ceres could help us work out how organics have spread in the Solar System. Note they are not a sign of life, but they include things like carbon, necessary ingredients for life on Earth.
Ceres itself does not appear to be habitable, although there are suggestions it has a subsurface ocean. So while we can’t say for now whether this is linked to life at all, it does pose some interesting questions. The statement noted that this finding had “important astrobiological implications.”
A paper published in Science in February this year first identified the organic-rich area on Ceres, abundant in aliphatic carbons. Researchers found methane and several types of common hydrocarbons, which are precursor molecules to amino acids, the building blocks of life.
Now that we know this material has been ever-present on Ceres, well, that opens up a whole new realm of study.