Rosetta flight director says Philae ready for release

Italian astronomers using the Hubble Space Telescope have tracked the rhythmic movement of two brown dwarf stars across the sky.

Views from Europe’s Rosetta comet orbiter show mysterious markings appearing on the nucleus of Comet 67P in recent months, with new surface features forming within a matter of weeks, and scientists are digging into the complex causes of the cometary erosion.

Delta (δ) Cephei, prototype of Cepheids, which has given its name to all similar variable stars, was discovered 230 years ago by the English astronomer John Goodricke. The Cepheids role as distance calibrators for more than a century means δ Cephei is one of the most studied stars, but astronomers were shocked to discover that they lacked an essential piece of information…