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Fast Radio Bursts Might Come From Nearby Stars

December 13, 2013 Leave a comment

Credit: NASA

Credit: NASA

First discovered in 2007, “fast radio bursts” continue to defy explanation. These cosmic chirps last for only a thousandth of a second. The characteristics of the radio pulses suggested that they came from galaxies billions of light-years away. However, new work points to a much closer origin – flaring stars within our own galaxy.

“We propose that fast radio bursts aren’t as exotic as astronomers first thought,” says lead author Avi Loeb of the Harvard-Smithsonian Center for Astrophysics (CfA).

Fast radio bursts are both brief and bright, packing a lot of energy into a short time. Only six have been discovered to date, all of them in archival data. Each was detected only once, making follow-up studies difficult.

A detailed analysis of the bursts showed that the pulses passed through a large column of electrons on their way to Earth. If those electrons were spread out across intergalactic space, then the pulses must have crossed billions of light-years. As a result, they would have to come from extremely energetic events. Gamma-ray bursts don’t produce the right radio frequencies, so astronomers looked to other extreme events like the collapse of a neutron star into a black hole.

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NASA’s Cassini Spacecraft Reveals Clues About Saturn Moon

December 13, 2013 Leave a comment

Image credit: NASA/JPL-Caltech/ASI/USGS

Image credit: NASA/JPL-Caltech/ASI/USGS

NASA’s Cassini spacecraft is providing scientists with key clues about Saturn’s moon Titan, and in particular, its hydrocarbon lakes and seas.

Titan is one of the most Earth-like places in the solar system, and the only place other than our planet that has stable liquid on its surface.

Cassini’s recent close flybys are bringing into sharper focus a region in Titan’s northern hemisphere that sparkles with almost all of the moon’s seas and lakes. Scientists working with the spacecraft’s radar instrument have put together the most detailed multi-image mosaic of that region to date. The image includes all the seas and most of the major lakes. Some of the flybys tracked over areas that previously were seen at a different angle, so researchers have been able to create a flyover of the area around Titan’s largest and second largest seas, known as Kraken Mare and Ligeia Mare, respectively, and some of the nearby lakes.

“Learning about surface features like lakes and seas helps us to understand how Titan’s liquids, solids and gases interact to make it so Earth-like,” said Steve Wall, acting radar team lead at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “While these two worlds aren’t exactly the same, it shows us more and more Earth-like processes as we get new views.”

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