3. Planetpalooza

Its name doesn’t exactly roll off the tongue, but HD 189733b is the planet of the year. A gas giant orbiting a yellow dwarf star roughly 63 light-years away, HD 189733b is the first exoplanet—short for extrasolar planet—for which astronomers have been able to produce a weather map. That map was created in May by a team led by Heather Knutson at Harvard University.