SternisheFan writes: —Volcanic activity in modern-day India, not an asteroid, may have killed the dinosaurs, according to a new study. Tens of thousands of years of lava flow from the Deccan Traps , a volcanic region near Mumbai in present-day India, may have spewed poisonous levels of sulfur and carbon dioxide into the atmosphere and caused the mass extinction through the resulting global warming and ocean acidification, the research suggests. The findings, presented Wednesday (Dec. 5) here at the annual meeting of the American Geophysical Union , are the latest volley in an ongoing debate over whether an asteroid or volcanism killed off the dinosaurs about 65 million years ago in the mass die-off known as the K-T extinction.
SternisheFan writes: The solar system that we live in is thought to have formed roughly 4.567 billion years ago, with the planets created out of an enormous disc of dust and gas in rotation around the sun. Similar processes are often observed around younger star systems all throughout the Milky Way, but until now it had been thought that the formation of our system had been an outlier, taking twice as long to form. But now, new research done using the uranium and lead dating of a type of primitive meteorite thought to have formed with the planets has suggested otherwise. “Using improved methods of analysis of uranium and lead isotopes, the current study of primitive meteorites has enabled researchers to date the formation of two very different types of materials, so-called calcium-aluminum-rich inclusions (or CAI’s for short) and chondrules, found within the same meteorite. By doing so, the chronology and therefore overall understanding of our solar system’s development has been altered.”
SternisheFan writes: "LOS ANGELES —US astronomers have found evidence of a star racing tightly around the monstrous black hole at the heart of our galaxy --the closest ever found near the matter-sucking body. The scientists from the University of California, Los Angeles, said the discovery will help them test Albert Einstein's theory of general relativity and his predictions of how black holes warp space and time. The star, S0-102, is orbiting the black hole every 11-and-a-half Earth years, much faster than the 60 years or longer orbit of most of the stars around the Milky Way's black hole center. This is only the second star discovered with such a short orbit --the other, S0-2, orbits the black hole every 16 years --thanks to improved imaging techniques. Lead researcher Andrea Ghez, who has been observing the black hole since she discovered it in 1998, said the second data point is crucial for their research.
"It is the tango of S0-102 and S0-2 that will reveal the true geometry of space and time near a black hole for the first time," she said in a statement. "This measurement cannot be done with one star alone." Like the Earth and other planets, both stars have elliptical orbits --meaning they regularly move closer and further from the black hole. Ghez and her team at UCLA hope to see evidence of little wobbles in the orbit when the stars move closer, which would show they are being affected by the curvature of space time, as predicted by Einstein's theory. Ghez added it was "phenomenal" to find two stars so close to the black hole. "This should not be a neighborhood where stars feel particularly welcome," she said. Black holes, which are what is left when a massive star dies and collapses in on itself, have a gravitational force so strong that even light cannot escape.
They cannot be seen directly, and so are observed through their influence on the things around them. "Now it's a whole new ballgame," Ghez said, adding that the team's investigations could open a new window into understanding black holes and how the universe evolves. The research will be published in Friday's issue of the US journal "Science.""