Scientists taking their first „sniffs of air“ from planets outside our solar system are a bit baffled by what they did not find: water. One of the more basic assumptions of astronomy is that the two distant, hot gaseous planets they examined must contain water in their atmospheres. The two suns the planets orbit closely have hydrogen and oxygen, the stable building blocks of water. These planets‘ atmospheres – examined for the first time using light spectra to determine the air’s chemical composition – are supposed to be made up of the same thing: good old H2O. But when two different teams of astronomers used NASA’s Spitzer Space Telescope for this new type of extrasolar planet research, they both came up dry, according to their studies published in Thursday’s edition of „Nature“ and the online version of the „Astrophysical Journal Letters“. The study of one planet found hints of fine silicate-particle clouds. Research on the other planet found no chemical fingerprints for any of the molecules scientists were seeking.
So far, scientists have found 213 planets outside our solar system, but only 14 have orbits that make it possible for this type of study; only eight or nine of those are close enough to see. One team studied the closest, which goes by the catchy name HD 189733b. It is about 360 trillion miles from Earth in the constellation Vulpecula. The other planet, HD 209458b, studied by the other team, is about 900 trillion miles away in the constellation Pegasus and it is the one with the strange silicate clouds.
NASA’s Spitzer First To Crack Open Light of Faraway Worlds

Off to one corner of NGC 346, a star cluster in the Small Magellanic Cloud, there’s an amazing collision between two stars. Well, not the stars themselves, but the powerful winds they are ejecting. The two stars are collectively known as HD 5980. They are a binary system of stars separated by only 90 million kilometres; this is roughly half the distance from the Earth to the Sun. One star has 50 times the mass of the Sun, while the other weighs in at 30 times the mass of the Sun. And both are radiating more than a million times the energy of the Sun. Both stars are producing terrifyingly strong solar winds, each dumping the mass of the Earth into space every month, and then accelerating this mass away with the pressure from all the photons they’re emitting. Since the stars are so close to each other, their solar winds interact. ESA’s XMM-Newton Observatory measured the X-ray output from this collision zone, and found that the energy from only X-rays is 10 times the amount of energy output by our own Sun.
First X-ray detection of a colliding-wind binary beyond the Milky Way

More than three centuries ago, Sir Isaac Newton reflected on the similarities between the sense of hearing and the sense of sight. Newton’s speculations were impossible to test scientifically – until now. A novel Brandeis University study confirms the Newtonian idea that sight and sound are indeed parallel – at least when it comes to encoding and retrieving short-term memories from the two senses.
K. Visscher, E. Kaplan, M.J. Kahana & R. Sekuler: Auditory short-term memory behaves like visual short-term memory (PDF, 975 KB)