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Archive for May 29, 2013

Forecast For Titan: Wild Weather Could Be Ahead


Ligeia Mare, the second largest known body of liquid on Saturn's moon Titan. Image credit: NASA/JPL-Caltech/ASI/Cornell

Ligeia Mare, the second largest known body of liquid on Saturn’s moon Titan. Image credit: NASA/JPL-Caltech/ASI/Cornell

Saturn’s moon Titan might be in for some wild weather as it heads into its spring and summer, if two new models are correct. Scientists think that as the seasons change in Titan’s northern hemisphere, waves could ripple across the moon’s hydrocarbon seas, and hurricanes could begin to swirl over these areas, too. The model predicting waves tries to explain data from the moon obtained so far by NASA’s Cassini spacecraft. Both models help mission team members plan when and where to look for unusual atmospheric disturbances as Titan summer approaches.

“If you think being a weather forecaster on Earth is difficult, it can be even more challenging at Titan,” said Scott Edgington, Cassini’s deputy project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We know there are weather processes similar to Earth’s at work on this strange world, but differences arise due to the presence of unfamiliar liquids like methane. We can’t wait for Cassini to tell us whether our forecasts are right as it continues its tour through Titan spring into the start of northern summer.”

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-170&cid=release_2013-170

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Researchers Reveal Model Of Sun’s Magnetic Field


Image credit: NASA Solar Dynamics Observatory

Image credit: NASA Solar Dynamics Observatory

Researchers at the Universities of Leeds and Chicago have uncovered an important mechanism behind the generation of astrophysical magnetic fields such as that of the Sun.

Scientists have known since the 18th Century that the Sun regularly oscillates between periods of high and low solar activity in an 11-year cycle, but have been unable to fully explain how this cycle is generated.

In the ‘Information Age’, it has become increasingly important to be able to understand the Sun’s magnetic activity, as it is the changes in its magnetic field that are responsible for ‘space weather’ phenomena, including solar flares and coronal mass ejections. When this weather heads in the direction of Earth it can damage satellites, endanger astronauts on the International Space Station and cause power grid outages on the ground.

The research, published in the journal Nature, explains how the cyclical nature of these large-scale magnetic fields emerges, providing a solution to the mathematical equations governing fluids and electromagnetism for a large astrophysical body.

Full Story: http://www.leeds.ac.uk/news/article/3402/researchers_reveal_model_of_suns_magnetic_field

NASA’s WISE Mission Finds Lost Asteroid Family Members


Data from NASA’s Wide-field Infrared Survey Explorer (WISE) have led to a new and improved family tree for asteroids in the main belt between Mars and Jupiter.

Astronomers used millions of infrared snapshots from the asteroid-hunting portion of the WISE all-sky survey, called NEOWISE, to identify 28 new asteroid families. The snapshots also helped place thousands of previously hidden and uncategorized asteroids into families for the first time. The findings are a critical step in understanding the origins of asteroid families, and the collisions thought to have created these rocky clans.

“NEOWISE has given us the data for a much more detailed look at the evolution of asteroids throughout the solar system,” said Lindley Johnson, the program executive for the Near-Earth Object Observation Program at NASA Headquarters in Washington. “This will help us trace the NEOs back to their sources and understand how some of them have migrated to orbits hazardous to the Earth.”

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-179

New ET Detection Method Leads To Quest For World’s Largest Telescope


Until recently, one of the ultimate mysteries of the universe — how many civilizations may exist on planets orbiting other stars in the Milky Way Galaxy — relied on the possibility of detecting intelligent beings by radio signals. Now a team of astronomers, engineers, and physicists from the University of Hawaii, the University of Freiburg, and elsewhere has proposed a new and powerful technique to search for intelligent life.

The revolutionary method is described by four of the team’s astronomers in the June 2013 issue of Astronomy magazine, the world’s largest magazine on the subject, with a print and web readership of half a million each month. The story, “How to Find ET with Infrared Light,” was written by Jeff R. Kuhn of the University of Hawaii’s Institute for Astronomy, Svetlana V. Berdyugina of the University of Freiburg and the Kiepenheuer Institute for Solar Physics in Germany, David Halliday of Dynamic Structures, Ltd., in British Columbia, and Caisey Harlingten of the Searchlight Observatory Network in The Grange, Norwich, England.

Rather than looking for radio waves, the team suggests searching for the heat signatures of nearby planets, which requires a giant telescope that could detect infrared radiation directly from an exoplanet, thus revealing the presence of a civilization.

“The energy footprint of life and civilization appears as infrared heat radiation,” says Kuhn, the project’s lead scientist. “A convenient way to describe the strength of this signal is in terms of total stellar power that is incident on the host planet.” The technique arises from the fact that a civilization produces power that adds to the heat on a planet, beyond the heat received from its host star. A large enough telescope, idealized for infrared detection, could survey planets orbiting stars within 60 light-years of the Sun to see whether or not they host civilizations.

Astronomy Magazine Article (PDF): http://www.astronomy.com/~/media/Files/PDF/Magazine%20articles/ET-with-infrared-light.pdf

Herschel Space Observatory Finds Galaxy Mega Merger


Image credit: ESA/NASA/JPL-Caltech/UC Irvine/STScI/Keck/NRAO/SAO

Image credit: ESA/NASA/JPL-Caltech/UC Irvine/STScI/Keck/NRAO/SAO

A massive and rare merging of two galaxies has been spotted in images taken by the Herschel space observatory, a European Space Agency mission with important NASA participation.

Follow-up studies by several telescopes on the ground and in space, including NASA’s Hubble Space Telescope and Spitzer Space Telescope, tell a tale of two faraway galaxies intertwined and furiously making stars. Eventually, the duo will settle down to form one super-giant elliptical galaxy.

The findings help explain a mystery in astronomy. Back when our universe was 3 billion to 4 billion years old, it was populated with large reddish elliptical-shaped galaxies made up of old stars. Scientists have wondered whether those galaxies built up slowly over time through the acquisitions of smaller galaxies, or formed more rapidly through powerful collisions between two large galaxies.

The new findings suggest massive mergers are responsible for the giant elliptical galaxies.

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-171
Also: http://news.uci.edu/press-releases/fragile-mega-galaxy-is-missing-link-in-history-of-cosmos/
Also: http://keckobservatory.org/news/fragile_mega_galaxy_is_missing_link_in_history_of_cosmos

NASA Hosts News And Social Media Events Around This Week’s Asteroid Pass


NASA is inviting members of the media and public to participate in online and television events May 30-31 with NASA officials and experts discussing the agency’s asteroid initiative and the Earth flyby of the 1.7-mile-long asteroid 1998 QE2.

At 4:59 p.m. EDT, Friday, May 31, 1998 QE2 will pass by Earth at a safe distance of about 3.6 million miles — its closest approach for at least the next two centuries. The asteroid was discovered Aug. 19, 1998, by the Massachusetts Institute of Technology’s Lincoln Near Earth Asteroid Research Program near Socorro, N.M.

Full Story, Times and Links: http://www.nasa.gov/home/hqnews/2013/may/HQ_M13-086_QE2_Asteriod_Events.html

NASA’s Swift Reveals New Phenomenon In A Neutron Star


Credit: ESA/XMM-Newton/M. Sasaki et al

Credit: ESA/XMM-Newton/M. Sasaki et al

Astronomers using NASA’s Swift X-ray Telescope have observed a spinning neutron star suddenly slowing down, yielding clues they can use to understand these extremely dense objects.

A neutron star is the crushed core of a massive star that ran out of fuel, collapsed under its own weight, and exploded as a supernova. A neutron star can spin as fast as 43,000 times per minute and boast a magnetic field a trillion times stronger than Earth’s. Matter within a neutron star is so dense a teaspoonful would weigh about a billion tons on Earth.

This neutron star, 1E 2259+586, is located about 10,000 light-years away toward the constellation Cassiopeia. It is one of about two dozen neutron stars called magnetars, which have very powerful magnetic fields and occasionally produce high-energy explosions or pulses.

Observations of X-ray pulses from 1E 2259+586 from July 2011 through mid-April 2012 indicated the magnetar’s rotation was gradually slowing from once every seven seconds, or about eight revolutions per minute. On April 28, 2012, data showed the spin rate had decreased abruptly, by 2.2 millionths of a second, and the magnetar was spinning down at a faster rate.

“Astronomers have witnessed hundreds of events, called glitches, associated with sudden increases in the spin of neutron stars, but this sudden spin-down caught us off guard,” said Victoria Kaspi, a professor of physics at McGill University in Montreal. She leads a team that uses Swift to monitor magnetars routinely.

Full Story: http://www.nasa.gov/mission_pages/swift/bursts/new-phenom.html