You can look up at the sky during almost any time of year and see some kind of astronomical occurrence -- meteor showers, planetary conjunctions, lunar and solar eclipses, and, for those of us in D.C., the well-known sight of the twice annual moon rising in line with the monuments. But few things have the celestial romance of seeing a comet in the sky. The last time we were able to see a comet from our roofdecks was in October 2007, when Comet Holmes burst to life a million times brighter, becoming as visible as the North Star. more ›