Gizmorama - November 25, 2013

Good Morning,

Have you always wondered why the Milky Way looks the way it does? Well, the Hubble telescope has capture the visual evidence to help answer that question.

Learn about this and other interesting stories from the scientific community in today's issue.

Until Next Time,
Erin

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*-- Hubble images help show what early Milky Way galaxy looked like --*
BALTIMORE - The Hubble telescope has provided the first visual evidence of how our galaxy, the Milky Way, became the majestic pinwheel of stars we see today, NASA says. Astronomers have analyzed Hubble's deep-sky surveys of 400 galaxies similar to the Milky Way to study their evolution and noted their appearance at various stages of development over a time span of 11 billion years, the space agency reported Thursday. The analysis suggests the Milky Way likely began as faint, blue, low-mass object containing lots of gas, fuel for subsequent star birth, astronomers said. A blue color is an indicator of rapid star formation, they said. From a flat disk with a bulge in the middle, the Milky Way would have slowly evolved into the majestic spiral form see today, they said. "For the first time, we have direct images of what the Milky Way looked like in the past," study co-leader Pieter G. van Dokkum of Yale University said. "Of course, we can't see the Milky Way itself in the past. We selected galaxies billions of light-years away that will evolve into galaxies like the Milky Way. "By tracing the Milky Way's siblings, we find that our galaxy built up 90 percent of its stars between 11 billion and 7 billion years ago, which is something that has not been measured directly before." At the peak of star formation, when the universe was about 4 billion years old, the Milky Way-like galaxies were pumping out about 15 stars a year. By comparison, the Milky Way today is creating only one star a year, the astronomers said.


*-- Experts: Ocean acidity may increase by 170 percent by end of century --*
PARIS - Global ocean acidity may increase by 170 percent by the end of the century, bringing significant economic losses, experts conclude in an international report. The group of experts has agreed on "levels of confidence" in relation to ocean acidification statements from the world's largest gathering of experts on ocean acidification ever convened, the International Council for Science reported from its Paris headquarters Thursday. "What we can now say with high levels of confidence about ocean acidification sends a clear message," Ulf Riebesell of the GEOMAR Helmholtz Center for Ocean Research in Kiel, Germany, said. "Globally we have to be prepared for significant economic and ecosystem service losses." Marine ecosystems and biodiversity are likely to change as a result of ocean acidification, with far-reaching consequences for society, the experts agreed. If society's high emissions are not curbed, cold-water coral reefs located in the deep sea may be unsustainable and tropical coral reef erosion is likely to outpace reef building this century, the experts said. However, they said, significant emissions reductions could ensure that half of surface waters presently occupied by tropical coral reefs remain favorable for their growth. Threats to ocean health would still remain, said report author Wendy Broadgate, Deputy Director at the International Geosphere-Biosphere Program. "Emissions reductions may protect some reefs and marine organisms but we know that the ocean is subject to many other stresses such as warming, deoxygenation, pollution and overfishing,"
she said.

"Reducing other stressors such as pollution and overfishing, and the introduction of large scale marine protected areas, may help build some resilience to ocean acidification."

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