For the first time ever, scientists have evidence of organic molecules on a dwarf planet in our Solar System. Ceres, the second-biggest object in the asteroid belt, is carrying molecules that contain carbon and ammonia—two chemicals crucial for all life on our own planet.
“Organic molecules are interesting to scientists because they are necessary, though not sufficient, components of life on Earth,” states NASA’s Jet Propulsion Laboratory.
According to the researchers, traces of organic compounds have previously been found on meteorites and asteroids, but this is the first time we have unambiguous evidence of such molecules on a main asteroid belt body.
Scientists used data from Dawn spacecraft’s visible and infrared mapping spectrometer to analyse various locations on the dwarf planet’s surface, and discovered a signature of the organic molecules in an area around the Ernutet Crater on Ceres’ northern hemisphere.
Previous Dawn mission findings have already shown hints of complex chemistry on Ceres, including water ice, salt, carbonates and ammonia.
Ceres has no clear signs of truly giant impact basins. This image shows both visible (left) and topographic (right) mapping data from Dawn. IMAGE CREDIT: NASA/JPL-Caltech/SwRI
What’s especially exciting about this discovery is the prospect that these molecules didn’t arrive on Ceres through collision with another object, which is how organic material usually travels through the solar system. According to the researchers, both the distribution and type of these compounds suggests they emerged locally.
A prominent feature of Ceres’ surface are plumes of water vapour that shoot up through patches of its icy surface. This suggests that there could be a subsurface ocean, and that the internal core of the dwarf planet is radiating heat. According to the study, these geological processes could have shot organic matter to the surface.
The team was only able to survey the middle latitude of Ceres, between 60 degrees north and south. The researchers believe it’s possible that organic molecules are also found in other areas.
This discovery adds to the growing body of exciting information we’ve so far gathered with the help of the Dawn spacecraft, which is still in an elliptical orbit around Ceres. In a few months’ time, the probe will be in a new position with the sun directly behind it, which will make Ceres brighter than we’ve seen before, and possibly yield new discoveries as well.
Header image: Enhanced colour composite image shows the area around Ernutet crater. The red areas around Ernutet are associated with evidence of organic material. IMAGE CREDIT: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA