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Stanford Solar Scientists Solve One Of The Sun’s Mysteries

August 28, 2013 Leave a comment

Credit: NASA SDO / HMI

Credit: NASA SDO / HMI

Stanford solar scientists have solved one of the few remaining fundamental mysteries of how the sun works.

The mechanism, known as meridional flow, works something like a conveyor belt. Magnetic plasma migrates north to south on the sun’s surface, from the equator to the poles, and then cycles into the sun’s interior on its way back to the equator.

The rate and depth beneath the surface of the sun at which this process occurs is critical for predicting the sun’s magnetic and flare activity, but has remained largely unknown until now.

Full Story: http://news.stanford.edu/pr/2013/pr-solar-magnetic-field-082913.html

New Cassini Data From Titan indicate A Rigid, Weathered Ice Shell

August 28, 2013 Leave a comment

An analysis of gravity and topography data from Saturn’s largest moon, Titan, has revealed unexpected features of the moon’s outer ice shell. The best explanation for the findings, the authors said, is that Titan’s ice shell is rigid and that relatively small topographic features on the surface are associated with large roots extending into the underlying ocean. The study is published in the August 29 issue of the journal Nature.

Led by planetary scientists Douglas Hemingway and Francis Nimmo at the University of California, Santa Cruz, the study used new data from NASA’s Cassini spacecraft. The researchers were surprised to find a negative correlation between the gravity and topography signals on Titan.

“Normally, if you fly over a mountain, you expect to see an increase in gravity due to the extra mass of the mountain. On Titan, when you fly over a mountain the gravity gets lower. That’s a very odd observation,” said Nimmo, a professor of Earth and planetary sciences at UC Santa Cruz.

Full Story: http://news.ucsc.edu/2013/08/titan-ice-shell.html

New Mexican Skies Protected With Dark Sky Park Designation

August 28, 2013 Leave a comment

"Milky Way, Fajada Butte" by Stan Honda

“Milky Way, Fajada Butte” by Stan Honda

The 34,000-acre Chaco Culture National Historical Park is home to many ancient wonders including the remains of a civilization that thrived over 1,000 years ago. The park, which has been protecting its archaeological riches since it was established in 1907, is now protecting its views of the starry skies too. It has just been named as the International Dark-Sky Associationʼs newest Dark Sky Park.

“Once the night sky was something that was very much a part of the human experience at Chaco and around the globe,” says IDA Executive Director Bob Parks. “We are delighted that Chaco is now preserving the nighttime environment alongside their historic treasures.”

As a Gold-tier IDA Dark Sky Park, Chaco has shown its commitment to preserving its near-pristine night skies. The park has adopted a set of strict lighting guidelines that include the use of dark-sky friendly lighting now and in the future, ensuring that it will do its part to keep the nighttime environment natural and unspoiled for generations to come.

Full Story: http://www.darksky.org/night-sky-conservation/338

Oldest Solar Twin Identified

August 28, 2013 Leave a comment

Astronomers have only been observing the Sun with telescopes for 400 years — a tiny fraction of the Sun’s age of 4.6 billion years. It is very hard to study the history and future evolution of our star, but we can do this by hunting for rare stars that are almost exactly like our own, but at different stages of their lives. Now astronomers have identified a star that is essentially an identical twin to our Sun, but 4 billion years older — almost like seeing a real version of the twin paradox in action.

Jorge Melendez (Universidade de São Paulo, Brazil), the leader of the team and co-author of the new paper explains: “For decades, astronomers have been searching for solar twins in order to know our own life-giving Sun better. But very few have been found since the first one was discovered in 1997. We have now obtained superb-quality spectra from the VLT and can scrutinise solar twins with extreme precision, to answer the question of whether the Sun is special.”

Full Story: http://www.eso.org/public/news/eso1337/