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Archive for August 7, 2013

Quasar Observed In 6 Separate Light Reflections


Quasars are active black holes – primarily from the early universe. Using a special method where you observe light that has been bent by gravity on its way through the universe, a group of physics students from the Niels Bohr Institute have observed a quasar whose light has been deflected and reflected in six separate images. This is the first time a quasar has been observed with so many light reflections. The results are published in the scientific journal, Astrophysical Journal.

“We had three hours to observe and already after one hour we had the first spectrum. It was a new experience for us, but we could see immediately that it was a quasar. A typical characteristic of a quasar is that the light has broad emission lines from gas close to the black hole. We were very excited and moved on to the other ‘candidates’ from observation and later that night we found yet another light reflection of the quasar,” explains Thejs Brinckmann, one of the astrophysics students working on the project. The other students in the group were Mikkel Kristensen, Mikkel Lindholmer and Anders Nielsen.

Full Story: http://www.nbi.ku.dk/english/news/news13/quasar-observed-in-6-separate-light-reflections/

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Two Very Different Gas Clouds In The Galaxy Next Door


Credit: ESO

Credit: ESO

ESO’s Very Large Telescope has captured an intriguing star-forming region in the Large Magellanic Cloud — one of the Milky Way’s satellite galaxies. This sharp image reveals two distinctive glowing clouds of gas: red-hued NGC 2014, and its blue neighbour NGC 2020. While they are very different, they were both sculpted by powerful stellar winds from extremely hot newborn stars that also radiate into the gas, causing it to glow brightly.

This image was taken by the Very Large Telescope (VLT) at ESO’s Paranal Observatory in Chile — the best place in the southern hemisphere for astronomical observing. But even without the help of telescopes like the VLT, a glance towards the southern constellation of Dorado (The Swordfish or Dolphinfish [1]) on a clear, dark night reveals a blurry patch which, at first sight, appears to be just like a cloud in the Earth’s atmosphere.

At least, this may have been explorer Ferdinand Magellan’s first impression during his famous voyage to the southern hemisphere in 1519. Although Magellan himself was killed in the Philippines before his return, his surviving crew announced the presence of this cloud and its smaller sibling when they returned to Europe, and these two small galaxies were later named in Magellan’s honour. However, they were undoubtedly seen by both earlier European explorers and observers in the southern hemisphere, although they were never reported.

Full Story and Images: http://www.eso.org/public/news/eso1335/

NASA Begins Launch Preparations For Next Mars Mission


NASA’s next spacecraft going to Mars arrived Friday, Aug. 2, at the agency’s Kennedy Space Center in Florida, and is now perched in a cleanroom to begin final preparations for its November launch.

The spacecraft will conduct the first mission dedicated to surveying the upper atmosphere of Mars. Scientists expect to obtain unprecedented data that will help them understand how the loss of atmospheric gas to space may have played a part in changing the planet’s climate.

“We’re excited and proud to ship the spacecraft right on schedule,” said David Mitchell, MAVEN project manager at NASA’s Goddard Space Flight Center in Greenbelt, Md. “But more critical milestones lie ahead before we accomplish our mission of collecting science data from Mars. I firmly believe the team is up to the task. Now we begin the final push to launch.”

Full Story: http://www.nasa.gov/press/2013/august/nasa-begins-launch-preparations-for-next-mars-mission/

Big Ice May Explain Mars’ Double-Layer Craters


Credit: NASA

Credit: NASA

Geologists from Brown University have developed a promising new explanation for a mysterious type of crater on the surface on Mars.

Double-layered ejecta craters or DLEs, like other craters, are surrounded by debris excavated by an impactor. What makes DLEs different is that the debris forms two distinct layers — a large outer layer with a smaller inner layer sitting on top. These distinctive craters were first documented in data returned from the Viking missions to Mars in the 1970s, and scientists have been trying ever since to figure out how the double-layer pattern forms.

A new study by Brown graduate student David Kutai Weiss and James W. Head, professor of geological science, suggests that DLEs are the result of impacts onto a surface that was covered by a layer of glacial ice tens of meters thick.

Full Story: http://news.brown.edu/pressreleases/2013/08/craters