Using data from Deep Impact, NASA astronomers put together a “recipe” for a comet’s ingredients. The ingredients were excavated from 9P/Tempel when Deep Impact’s impactor hit its surface. Astronomers found evidence that the comet included clay, iron-containing compounds, carbonates (the minerals in seashells), crystallized silicates such as the green olivine minerals found on beaches, as well as polycyclic aromatic hydrocarbons, carbon-containing compounds found in car exhaust and on burnt toast. Deep Impact also found evidence of water vapor and carbon dioxide gas.

The ingredients pictured here are: (back, from left to right) a cup of ice and a cup of dry ice; (in measuring cups, from left to right) olivine, clay, polycyclic aromatic hydrocarbons, spinel, metallic iron; (front, from left to right) the silicate enstatite, the carbonate dolomite, and the iron sulfide marcasite.

Courtesy of George Rossman of the California Institute of Technology | Credit: NASA/JPL-Caltech