Our galaxy’s explosive past
A massive energy flare tore through the heart of our galaxy some 3.5 million years ago—a blast so powerful, it could be felt 200,000 light-years away and may have lasted some 300,000 years. That’s the conclusion of a new study by researchers in Australia and the U.S., a finding that, if confirmed, could upend our understanding of the Milky Way. “We always thought about our galaxy as an inactive galaxy,” co-author Magda Guglielmo, from the University of Sydney, tells USNews.com. “These new results instead open the possibility of a complete reinterpretation of its evolution and nature.” Basing their research on data from the Hubble Space Telescope, the astronomers believe the Seyfert flare was triggered by nuclear activity near Sagittarius A*, the supermassive black hole at the center of the galaxy. The flare, they say, created two “ionization cones” that ripped through the Milky Way and left their mark on the Magellanic Stream—a long trail of gas that partially circles the galaxy. “The flare must have been a bit like a lighthouse beam,” says co-author Joss Bland-Hawthorn. “Imagine darkness, and then someone switches on a lighthouse beacon.”
Cases of primary and secondary syphilis— the most infectious stages—increased 14 percent year over year, to more than 35,000; gonorrhea cases rose 5 percent to more than 580,000; and chlamydia increased 3 percent, to more than 1.7 million. “Not that long ago, gonorrhea rates were at historic lows, syphilis was close to elimination, and we were able to point to advances in STD prevention,” says Gail Bolan from the Centers for Disease Control and Prevention. “That progress has since unraveled.” Health officials say more people are being screened for STDs, which means that more cases are being logged. But they also say fewer people are using condoms, particularly among highrisk populations such as sexually active high schoolers and men who have sex with men. One especially worrying trend, reports CNN .com, is the rise in congenital syphilis. That debilitating and deadly infection occurs when the disease passes from a pregnant mother to her fetus through the placenta. More than 1,300 infants were born with congenital syphilis last year; 94 of them died.
months to prepare for the arrival of piglets. Colleagues who returned to the zoo the next spring confirmed her theory. Three of the four pigs in the pen were using tools to create a homey nest: a pit filled with leaves. Subsequent visits yielded the same finding. Root-Bernstein says it isn’t yet clear why the pigs use tools, given that their snouts appear better suited for the task. “Learned things and cultural things work that way,” she tells NationalGeographic.com. “Maybe it just feels like the right thing to do.”