Atom & Cosmos

Runaway planets
Some elderly stars may kick a planet out of house and home, University of Cambridge astronomers in England report in an upcoming Monthly Notices of the Royal Astronomical Society. Several exoplanets have been discovered orbiting stars that are past their prime, or even dead, and it has been a mystery how the stars’ age affects the fate of the planets. In the new study, researchers found that the mass loss suffered by an aging star may knock an orbiting planet off course, even ejecting it from orbit entirely. —Camille Carlisle

Neptune back where it was found
On July 12 Neptune arrived at the same patch of space in which it was first discovered 165 years ago. It takes the slow-moving gas giant that long to complete one revolution around the sun, which it orbits at a distance of 4.5 billion kilometers. German astronomer Johann Galle discovered the planet on September 23, 1846, at the prompting of predictions based on Uranus’ orbit and Newton’s law of gravity. The planet was the first body discovered using math instead of serendipity. Astronomers have since learned a lot about Neptune — such as finding its Great Dark Spot and seeing its clouds change with the planet’s 40-year seasons. —Camille Carlisle 

Goodbye antineutrino
Those flighty particles called neutrinos have a new trick up their sleeve. One kind, called the muon antineutrino, behaves differently from its counterpart, the muon neutrino. Physicists with the MINOS collaboration, working at the Fermi National Accelerator Laboratory in Batavia, Ill., shoot neutrinos and antineutrinos along a 735-kilometer path and watch as they disappear, presumably by transforming into other particles. The researchers have now seen a muon antineutrino vanish for the first time, they report online July 5 in Physical Review Letters. Measurements of the physical properties of its disappearance don’t match those of its counterpart. If scientists can’t rule out several easy explanations, new physics may be in play. —Alexandra Witze

Nazdarovya! Russia launches radio telescope
Russia launched a space-based radio telescope from the Baikonur Cosmodrome in Kazakhstan on July 18. Flying in an elliptical orbit, the Spektr-R telescope will reach a peak distance of more than 300,000 kilometers from Earth — almost the distance to the moon. When networked with ground-based detectors, the 10-meter telescope and its partners will form a virtual “dish” roughly 30 times the diameter of the Earth — the largest yet. Thousands of times more powerful than the Hubble Space Telescope, the superdish will peer closely at black holes, pulsars, neutron stars and other cosmic phenomena. Telescopes at the National Radio Astronomy Observatory in Greenbank, W. Va., and in Arecibo, Puerto Rico are anticipated to act as Earth-bound partners. —Nadia Drake