ikenbot:

Goat Aurora Over Greenland

Sometimes it’s hard to believe what you see in the sky. During the Shelios Expedition to Greenland in late August, even veteran sky enthusiasts saw auroras so colorful, so fast changing, and so unusual in form that they could remember nothing like it.

Image Credit & Copyright: Juan Carlos Casado (TWAN)

As the ever changing auroras evolved, huge shapes spread across the sky morphed from one familiar form into another, including what looked to be the head of a goat (shown above), the head of an elephant, a strange green-tailed comet, and fingers on a celestial hand.

Even without the aurora, the sky would be notable for the arching band of our Milky Way Galaxy and the interesting field of stars, nebulas, and galaxies. In contrast, in the foreground is a farm house in Tasiusaq, Kujalleq. Greenland. The Shelios project exists not only to observe auroras but to motivate students to consider a career in science.

ikenbot:

Goat Aurora Over Greenland

Sometimes it’s hard to believe what you see in the sky. During the Shelios Expedition to Greenland in late August, even veteran sky enthusiasts saw auroras so colorful, so fast changing, and so unusual in form that they could remember nothing like it.

Image Credit & Copyright: Juan Carlos Casado (TWAN)

As the ever changing auroras evolved, huge shapes spread across the sky morphed from one familiar form into another, including what looked to be the head of a goat (shown above), the head of an elephant, a strange green-tailed comet, and fingers on a celestial hand.

Even without the aurora, the sky would be notable for the arching band of our Milky Way Galaxy and the interesting field of stars, nebulas, and galaxies. In contrast, in the foreground is a farm house in Tasiusaq, Kujalleq. Greenland. The Shelios project exists not only to observe auroras but to motivate students to consider a career in science.

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Posted 2 years ago on Thursday 4 October 2012 with 2,650 notes .
mothernaturenetwork:

Photo of the day: A glowing burst of green aurora lights up the sky in the early hours of Oct. 1 above Whitehorse, Yukon, Canada. The light show was the result of a coronal mass ejection that erupted from the sun 3 days earlier. As long, dark winter nights descend on the northern hemisphere, aurora lovers in far north towns and cities will have plenty of opportunity to witness these stunning displays. The peak time to view auroras occurs between 11 a.m. and 2 a.m., and the most active displays occur in the equinox months of September and March.

mothernaturenetwork:

Photo of the day: A glowing burst of green aurora lights up the sky in the early hours of Oct. 1 above Whitehorse, Yukon, Canada. The light show was the result of a coronal mass ejection that erupted from the sun 3 days earlier.
 
As long, dark winter nights descend on the northern hemisphere, aurora lovers in far north towns and cities will have plenty of opportunity to witness these stunning displays. The peak time to view auroras occurs between 11 a.m. and 2 a.m., and the most active displays occur in the equinox months of September and March.

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Posted 2 years ago on Thursday 4 October 2012 with 401 notes .
What happens when Super massive black holes merge? 

 https://www.google.com/producer/editions/CAowiY0T/universe_today/CAIiEEQPYOlFFdgf32u5MWpt-0gqMggEIhCpLHq8JeKU2rDfXWaqFuQ1KhwIACIQda5Twl-mEu76ReEdJCeE9yoGCAowiY0T/what_happens_when_supermassive_b
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Posted 2 years ago on Wednesday 3 October 2012 .
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Posted 2 years ago on Tuesday 29 May 2012 with 1,110 notes .
New Evidence Suggests Comets Carried Life to Earth

New Evidence Suggests Comets Carried Life To Earth

http://www.redorbit.com/news/space/1112503161/new-evidence-suggests-comets-carried-life-to-earth/


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Posted 2 years ago on Thursday 29 March 2012 with 14 notes .
the-star-stuff:

The Filipina who proved Einstein right
Meet  Reinabelle Reyes, a 28-year-old astrophysicist who astounded scientists all over the world when she proved Einstein’s Theory of General Relativity on a cosmic scale. That was when she was only 26.
Einstein’s theories have been verified many times, but it took Reyes and her Princeton University collaborators to verify his Theory of General Relativity, beyond the confines of our solar system.
Led by Reyes, the research team made headlines back in 2010 when they showed how galaxies up to 3.5 billion light years away are clustered together in exactly the way General Relativity predicts. They came up with a new astronomical measurement, which indicates how galaxies are pulled together by gravity, just as Einstein theorized.
Her findings also support the existence of Dark Energy—a force greater than gravity once merely imagined by scientists. This is a big deal, because, even NASA tells us, pinning down the exact properties of Dark Energy is among the most significant problems facing science today. According to the NASA website, Dark Energy “is the deepest mystery in physics, and its resolution is likely to greatly advance our understanding of matter, space, and time.”
Reinabelle Reyes is among the scientists involved in unraveling this profound mystery.
READ MORE!!!!

the-star-stuff:

The Filipina who proved Einstein right

Meet  Reinabelle Reyes, a 28-year-old astrophysicist who astounded scientists all over the world when she proved Einstein’s Theory of General Relativity on a cosmic scale. That was when she was only 26.

Einstein’s theories have been verified many times, but it took Reyes and her Princeton University collaborators to verify his Theory of General Relativity, beyond the confines of our solar system.

Led by Reyes, the research team made headlines back in 2010 when they showed how galaxies up to 3.5 billion light years away are clustered together in exactly the way General Relativity predicts. They came up with a new astronomical measurement, which indicates how galaxies are pulled together by gravity, just as Einstein theorized.

Her findings also support the existence of Dark Energy—a force greater than gravity once merely imagined by scientists. This is a big deal, because, even NASA tells us, pinning down the exact properties of Dark Energy is among the most significant problems facing science today. According to the NASA website, Dark Energy “is the deepest mystery in physics, and its resolution is likely to greatly advance our understanding of matter, space, and time.”

Reinabelle Reyes is among the scientists involved in unraveling this profound mystery.

READ MORE!!!!

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Posted 2 years ago on Tuesday 20 March 2012 with 3,703 notes .
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Posted 2 years ago on Tuesday 13 March 2012 with 133 notes .
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Dark Matter Blob Should Not Exist, But There It Is
Dark matter, galaxies, and hot gas merge in the core of the galaxy cluster Abell 520 in a composite image.

An unusual patch of sky devoid of galaxies could hint at the existence of more than one type of dark matter, scientists say.
Dark matter at the center of Abell 520, a cosmic “train wreck” of galaxy clusters located about 2.4 billion light-years away, is not behaving as predicted, according to new results from NASA’s Hubble Space Telescope.
Dark matter is a mysterious substance that appears to make up almost a quarter of the universe but cannot be detected with current instruments. Theory predicts that dark matter clusters, or “halos,” form gravitational anchors around which normal matter can coalesce to form galaxies.
When galaxies and galaxy clusters crash into one another, their dark matter skeletons also collide. Because normal matter is gravitationally attracted to dark matter, the visible tatters of the colliding galaxies should be dragged along, like dogs on leashes.
This is in fact what astronomers observed in 2006 in the Bullet Cluster (pictured), which is a textbook example of how dark matter should behave.
During the same 2006 research, astronomers examining Abell 520 found that its dark matter is concentrated in a “dark core” that contains far fewer galaxies than would be expected if the dark matter and galaxies had stuck together. Most of the galaxies have apparently sailed far away from the collision.
"It is very hard to explain this with current theories of dark matter or galaxy formation," said study co-author Myungkook James Jee at the University of California, Davis.
Dark Matter Results Puzzling
The 2006 results were so unexpected that some scientists dismissed them. But the recent Hubble analysis backs up those initial observations, leaving astronomers as puzzled as ever.
"We tried to come up with models that would explain this, but there were not any good models," study co-author Andisheh Mahdavi, an astronomer at San Francisco State University, said in a statement.
"There is no way that you could have cold dark matter piling up like this in a region with so few galaxies," said Mahdavi, who was involved in the 2006 observations.
(See "Dark-Matter Galaxy Detected: Hidden Dwarf Lurks Nearby?")
The team has proposed several explanations for their findings, but none of them can be accounted for by current dark matter theory. One idea is that there are more than one type of dark matter, and that some varieties clump together during collisions while others do not.
"If there is more than one species of dark matter, one could be collisionless and the other could be collisional," said study co-author Jee, whose study was recently published online in the Astrophysical Journal.
"But that is all very speculative right now."

Dark Matter Theories in Question?
Another possibility is that Abell 520 involves a collision between three galaxy clusters, instead of just two systems, as in the case of the Bullet Cluster. The result would be a more complicated interaction, experts say.
For instance, “one can imagine a transient structure exhibiting a dark matter peak without galaxies,” said Avi Loeb, chair of the astronomy department at Harvard University. (See galaxy pictures.)
Computer simulations of Abell 520 could help resolve the mystery by helping to calculate just how likely it is that Abell 520’s dark matter core could exist, added Loeb, who was not involved in the study.
"Without such a statistical analysis, it is premature to conclude that the observed structure is unlikely."
The team says plans are already underway to conduct computer simulations to try to explain Abell 520. But if the simulations fail, particle physicists may have to revise their theories about dark matter, co-author Mahdavi said.
"I’m just as perplexed as I was back in 2007," he added. "It’s a pretty disturbing observation to have out there."
Ker Than
for National Geographic News
Published March 6, 2012

Dark Matter Blob Should Not Exist, But There It Is

Dark matter, galaxies, and hot gas merge in the core of the galaxy cluster Abell 520 in a composite image.

An unusual patch of sky devoid of galaxies could hint at the existence of more than one type of dark matter, scientists say.

Dark matter at the center of Abell 520, a cosmic “train wreck” of galaxy clusters located about 2.4 billion light-years away, is not behaving as predicted, according to new results from NASA’s Hubble Space Telescope.

Dark matter is a mysterious substance that appears to make up almost a quarter of the universe but cannot be detected with current instruments. Theory predicts that dark matter clusters, or “halos,” form gravitational anchors around which normal matter can coalesce to form galaxies.

When galaxies and galaxy clusters crash into one another, their dark matter skeletons also collide. Because normal matter is gravitationally attracted to dark matter, the visible tatters of the colliding galaxies should be dragged along, like dogs on leashes.

This is in fact what astronomers observed in 2006 in the Bullet Cluster (pictured), which is a textbook example of how dark matter should behave.

During the same 2006 research, astronomers examining Abell 520 found that its dark matter is concentrated in a “dark core” that contains far fewer galaxies than would be expected if the dark matter and galaxies had stuck together. Most of the galaxies have apparently sailed far away from the collision.

"It is very hard to explain this with current theories of dark matter or galaxy formation," said study co-author Myungkook James Jee at the University of California, Davis.

Dark Matter Results Puzzling

The 2006 results were so unexpected that some scientists dismissed them. But the recent Hubble analysis backs up those initial observations, leaving astronomers as puzzled as ever.

"We tried to come up with models that would explain this, but there were not any good models," study co-author Andisheh Mahdavi, an astronomer at San Francisco State University, said in a statement.

"There is no way that you could have cold dark matter piling up like this in a region with so few galaxies," said Mahdavi, who was involved in the 2006 observations.

(See "Dark-Matter Galaxy Detected: Hidden Dwarf Lurks Nearby?")

The team has proposed several explanations for their findings, but none of them can be accounted for by current dark matter theory. One idea is that there are more than one type of dark matter, and that some varieties clump together during collisions while others do not.

"If there is more than one species of dark matter, one could be collisionless and the other could be collisional," said study co-author Jee, whose study was recently published online in the Astrophysical Journal.

"But that is all very speculative right now."

Dark Matter Theories in Question?

Another possibility is that Abell 520 involves a collision between three galaxy clusters, instead of just two systems, as in the case of the Bullet Cluster. The result would be a more complicated interaction, experts say.

For instance, “one can imagine a transient structure exhibiting a dark matter peak without galaxies,” said Avi Loeb, chair of the astronomy department at Harvard University. (See galaxy pictures.)

Computer simulations of Abell 520 could help resolve the mystery by helping to calculate just how likely it is that Abell 520’s dark matter core could exist, added Loeb, who was not involved in the study.

"Without such a statistical analysis, it is premature to conclude that the observed structure is unlikely."

The team says plans are already underway to conduct computer simulations to try to explain Abell 520. But if the simulations fail, particle physicists may have to revise their theories about dark matter, co-author Mahdavi said.

"I’m just as perplexed as I was back in 2007," he added. "It’s a pretty disturbing observation to have out there."

Ker Than

for National Geographic News

Published March 6, 2012

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Posted 2 years ago on Tuesday 13 March 2012 with 1 note .
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