Sweeping Ceres for the Building Blocks of Life

The Dawn spacecraft has detected for the first time evidence of organic compounds on the dwarf planet.

The surface of Ceres, the largest object in the asteroid belt
Here be organic compounds. (NASA)

Scientists are discovering more ingredients for life on Ceres.

For the first time, researchers have detected organic compounds on the dwarf planet, the second-biggest object in the asteroid belt between Mars and Jupiter. The materials contain hints of carbon and ammonia, the chemical components that exist in all known life on Earth. The scientists don’t know exactly what these compounds are, but they say they resemble some tar-like substances that can be found here.

The findings, described in a study published Thursday in the journal Science, come from data collected by the Dawn spacecraft, which NASA launched in 2007 to study Ceres and its neighbor inside the asteroid belt, Vesta. Previous observations by Dawn, as well as space telescopes, have shown evidence of water ice, ammonia, salt, and carbonates—all ingredients necessary to create a spark that could, under the right conditions, lead to life.

The researchers specifically used data from Dawn’s visible and infrared mapping spectrometer. The instrument sweeps the surface of Ceres for thermal radiation, which can provide information about its chemical composition. The data showed an unusually high concentration of organic material near Ernutet, a 32-mile-wide crater in Ceres’s northern hemisphere. More material was detected scattered in the area near the crater. The researchers believe the compounds originated on Ceres, and did not arrive on the asteroid through a collision with another object, a common delivery method within the solar system. The compounds, they say, wouldn’t have survived the extreme heat of such an impact, and their distribution on Ceres’s surface doesn’t match up with the type that a cosmic accident might produce.

It’s important to note that organic compounds can exist where life itself doesn’t. But Ceres is, in other ways, alive. Plumes of water vapor shoot out from underneath the surface when parts of its icy surface melt enough to let them through. The plumes could suggest an internal heat inside the asteroid, left over from its formation 4.6 billion years ago. They could also be evidence of remnants of an ancient ocean. The researchers behind the Science study say internal rumblings could have brought those organic compounds to the surface.

The findings build on the growing body of research of what made Ceres, and what makes it tick. Ceres formed alongside the planets about 4.5 billion years ago, as clouds and gas and dust swirled the guts of the solar system into existence. Studying Ceres could provide humans with a better understanding of the origins of life on Earth—and why we haven’t found it elsewhere in the solar system.