NASA says organic molecules are necessary but not sufficient for life
A NASA probe has found evidence of organic material on Ceres - a dwarf planet between Mars and Jupiter.
The discovery was made as part of its Dawn mission, using the spacecraft's visible and infrared mapping spectrometer.
Scientists detected the material in and around a northern-hemisphere crater called Ernutet.
NASA says organic molecules are necessary, though not sufficient, components of life on Earth.
The discovery adds to the growing list of bodies in the solar system where organics have been found.
Organic compounds have been found in meteorites, as well as inferred from telescopic observations of several asteroids.
NASA says: "Ceres shares many commonalities with meteorites rich in water and organics - in particular, a meteorite group called carbonaceous chondrites.
"This discovery further strengthens the connection between Ceres, these meteorites and their parent bodies."
Maria Cristina De Sanctis is lead author of the study, based at the National Institute of Astrophysics in Rome.
"This is the first clear detection of organic molecules from orbit on a main belt body", she said.
The discovery is reported in the journal Science.
Data presented in the paper support the idea that the organic materials are native to Ceres.
The carbonates and clays previously identified there provide evidence for chemical activity in the presence of water and heat.
This raises the possibility that the organics were similarly processed in a warm water-rich environment.
In enhanced visible colour images from Dawn's framing camera, the organic material is associated with areas that appear more red, with respect to the rest of Ceres.
The distinct nature of these regions stands out even in low-resolution image data from the visible and infrared mapping spectrometer.
"We're still working on understanding the geological context for these materials," said study co-author Carle Pieters, professor of geological sciences at Brown University in Rhode Island.
Having completed nearly two years of observations in orbit at Ceres, Dawn is now in a highly elliptical orbit at Ceres, going from an altitude of 7,520 kilometers up to almost 9,350 kilometers.
Later this month, it will make its way to a new altitude to study Ceres in a new geometry.
While in late spring, Dawn will view Ceres with the sun directly behind the spacecraft, and perhaps reveal more clues about its nature.