Researchers have long hypothesized that comets helped to seed the Earth with the organic material necessary for life to form. In August, the Rosetta probe detected several organic molecules in the comet's gaseous wake, including water, carbon monoxide, carbon dioxide, ammonia, methane and methanol, the Journal writes. But this is the first time, the Guardian adds, that we've been able to directly sample a comet directly for the presence of complex compounds. Studying which molecules are present and attempting to determine how they form can potentially lend insight into the history of life on our own planet.