Impact Experiments Probe the Origin of Organics on the Dwarf Planet Ceres
Side view of the ejecta curtain created during a hypervelocity impact experiment at the NASA Ames Vertical Gun Range. The experiment was designed to investigate the effects of impacts on Ceres’ organics.
NASA/Johns Hopkins University Applied Physics Laboratory
One of the most exciting findings from NASA's Dawn mission is that Ceres, the largest object in the asteroid belt that lies between Mars and Jupiter, hosts complex organics. The discovery of aliphatic molecules, which consist of carbon and hydrogen chains, in conjunction with evidence that Ceres has abundant water ice and may have been an ocean world, means this dwarf planet might have once harbored the main ingredients associated with life as we know it.
How the aliphatic organics originated on Ceres has been the subject of intensive research since their discovery in 2017. Some studies have concluded that a comet or other organic-rich impactor delivered them to Ceres; others indicate the molecules formed on the dwarf planet after its primordial materials were altered by briny water. But regardless of their origin, the organics on Ceres have been affected by the pervasive impacts that have pockmarked its surface.
Now new research to be presented Tuesday at the Geological Society of America's GSA Connects 2023 meeting is extending scientists' understanding of how impacts have affected Ceres' aliphatic molecules—and what the implications are for determining their origin and assessing the dwarf planet's habitability.
"The organics were initially detected in the vicinity of a large impact crater, which is what motivated us to look at how impacts affect these organics," says Terik Daly, a planetary scientist at the Johns Hopkins Applied Physics Laboratory who led this study. "We are finding that organics may be more widespread than first reported and that they seem to be resilient to impacts with Ceres-like conditions."