Despite its solid appearance, 67P is highly porous with a density similar to wood or cork and orbited by a cloud of approximately 100,000 “grains” of material larger than 2 inches (5 cm) across stranded there after the comet’s previous perihelion passage. ... Researchers have identified 19 distinct geological regions on the comet and five basic types of terrain: dust-covered, brittle material, large-scale depressions, smooth terrains and consolidated surfaces. ... Using a spectrometer to scan the comet’s surface researchers discovered complex organic (carbon-based) molecules that could include carboxylic acids – a component of amino acids. These organics only form in...