Comet 67P/Churyumov-Gerasimenko (I’ll call it Comet 67P) has been minding its own business for billions of years as it quietly looped around the Sun every 6.5 years. Discovered in 1969 by astronomers Klim Ivanovych Churyumov and Svetlana Ivanovna Gerasimenko, it spins around on its own axis every 12 hours and is about 2 miles across. …

On August 6, 2014 after a decade-long journey chasing its target, ESA’s Rosetta has today become the first spacecraft to rendezvous with a comet, opening a new chapter in Solar System exploration. Comet 67P/Churyumov–Gerasimenko and Rosetta now lie 405 million kilometers from Earth, about half way between the orbits of Jupiter and Mars, rushing towards …