News Scan Briefs; October 2005; Scientific American Magazine; by JR Minkel, Charles Q. Choi; 2 Page(s)

News of another "planet" beyond Pluto may become common. First came Quaoar in 2002 and then Sedna in 2003. Unlike these two worlds, the latest candidate, announced in July, is actually bigger than Pluto, by 50 percent. Designated 2003UB313 and unoffi cially nicknamed Xena, the mass of ice and rock currently lies three times farther out than Pluto. Investigators originally photographed it in 2003 at Palomar Observatory near Los Angeles, but its strange orbit, tilted nearly 45 degrees off that of nearly all other planets, delayed its discovery until this past January. Near-infrared images reveal a surface of mostly methane ice, remarkably similar to Pluto's. One or two more planets of like size might dwell within the same distance, says planetary scientist Michael Brown of the California Institute of Technology. An untold number of worlds might lurk beyond that, perhaps deriving from the Kuiper belt or the hypothesized Oort cloud. "No one has really probed out to that distance," he remarks.

In 2001 a controversial Nature paper reported that genetically modified corn ended up where none should be in the Mexican state of Oaxaca, raising concern that the transgenic varieties might invade the natural population. The journal disavowed that paper the next year on insufficient evidence, but subsequent Mexican government studies backed it. New research supports Nature's disavowal. Mexican and U.S. researchers analyzed nearly 154,000 seeds from 870 maize plants in 125 fields over two years in Oaxaca, looking for traces of engineered genes. After expecting a transgenic presence as high as 5 or 10 percent, they were surprised to find no traces. The scientists suggest transgenic maize may not have survived in the harsh mountain climate and soil in which indigenous corn mainly grows and that local farmers may have taken extra precautions with their seed stocks after they became aware of potentially uninvited genes. The Proceedings of the National Academy of Sciences USA published the findings online August 10.