Finding out whether just a few or many of this newfound type of rocky object roam deep space should help scientists sort among contrasting scenarios of the solar system's infancy.
Comets
Cracks on Comets Most Likely Caused by Thermal Stress
Networks of cracks in the surface of 67P/Churyumov-Gerasimenko may have originated from rapid heating and cooling of the comet's surface.
Comet Lander Makes a Hard Discovery
The Philae probe, dropped onto a comet by the Rosetta spacecraft, has made contact with a surface thought too hard to be on a comet and has detected a few organic molecules new to comet exploration.
Philae Scientists Make Plans for Revived Mission
With their robotic explorer awake again, Philae's handlers get ready to give Comet 67P-Churyumov-Gerasimenko renewed scrutiny and to get a better bead on where the lander clings to the spinning orb of rock and ice.
