Huge Star-Quake Rocks Milky Way

[onedomino]

Huge Star-Quake Rocks Milky Way

http://news.bbc.co.uk/1/hi/sci/tech/4278005.stm

Astronomers say they have been stunned by the amount of energy released in a star explosion on the far side of our galaxy, 50,000 light-years away. The flash of radiation on 27 December was so powerful that it bounced off the Moon and lit up the Earth's atmosphere.

The blast occurred on the surface of an exotic kind of star - a super-magnetic neutron star called SGR 1806-20.

If the explosion had been within just 10 light-years, Earth could have suffered a mass extinction, it is said.

"We figure that it's probably the biggest explosion observed by humans within our galaxy since Johannes Kepler saw his supernova in 1604," Dr Rob Fender, of Southampton University, UK, told the BBC News website.
One calculation has the giant flare on SGR 1806-20 unleashing about 10,000 trillion trillion trillion watts.

"This is a once-in-a-lifetime event. We have observed an object only 20km across, on the other side of our galaxy, releasing more energy in a 10th of a second than the Sun emits in 100,000 years," said Dr Fender.

The event overwhelmed detectors on space-borne telescopes, such as the recently launched Swift observatory.

This facility was put above the Earth to detect and analyse gamma-ray bursts - very intense but fleeting flashes of radiation.

The giant flare it and other instruments caught in December has left scientists scrabbling for superlatives.

Twenty institutes from around the world have joined the investigation and two teams are to report their findings in a forthcoming issue of the journal Nature.

The light detected from the giant flare was far brighter in gamma-rays than visible light or X-rays.

Research teams say the event can be traced to the magnetar SGR 1806-20.
This remarkable super-dense object is a neutron star - it is composed entirely of neutrons and is the remnant collapsed core of a once giant star.
Now, though, this remnant is just 20km across and spins so fast it completes one revolution every 7.5 seconds.

"It has this super-strong magnetic field and this produces some kind of structure which has undergone a rearrangement - it's an event that is sometimes characterised as a 'star-quake', a neutron star equivalent of an earthquake," explained Dr Fender.

"It's the only possible way we can think of releasing so much energy."
Continued glow

SGR 1806-20 is sited in the southern constellation Sagittarius. Its distance puts it beyond the centre of the Milky Way and a safe distance from Earth.

"Had this happened within 10 light-years of us, it would have severely damaged our atmosphere and would possibly have triggered a mass extinction," said Dr Bryan Gaensler, of the Harvard-Smithsonian Center for Astrophysics, who is the lead author on one of the forthcoming Nature papers.

"Fortunately there are no magnetars anywhere near us."

The initial burst of high-energy radiation subsided quickly but there continues to be an afterglow at longer radio wavelengths.

This radio emission persists as the shockwave from the explosion moves out through space, ploughing through nearby gas and exciting matter to extraordinary energies.

"We may go on observing this radio source for much of this year," Dr Fender said.

This work is being done at several centres around the globe, including at the UK's Multi-Element Radio-Linked Interferometer Network (Merlin) and the Joint Institute for VLBI (Very Long Baseline for Interferometry) in Europe - both large networks of linked radio telescopes.

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[KarlMarx]

I guess we're more blessed than we realize. Yes, it is a good thing that stars such as this aren't near by. But then perhaps that's why life exists on this planet in the first place. Perhaps this might help to explain why there doesn't seem to be any life out there. Perhaps there are very few "safe zones" where life can exist long enough to reach the point of becoming intelligent, much less advanced enough to contact other civilizations.

So when this star exploded 50,000 years ago... modern man hadn't even appeared yet, humans had not yet reached Europe and the Earth was in the grip of an ice age.... writing and civilization would not appear for another 45,000 years....

 

[onedomino]

I guess we're more blessed than we realize. Yes, it is a good thing that stars such as this aren't near by. But then perhaps that's why life exists on this planet in the first place. Perhaps this might help to explain why there doesn't seem to be any life out there. Perhaps there are very few "safe zones" where life can exist long enough to reach the point of becoming intelligent, much less advanced enough to contact other civilizations.

So when this star exploded 50,000 years ago... modern man hadn't even appeared yet, humans had not yet reached Europe and the Earth was in the grip of an ice age.... writing and civilization would not appear for another 45,000 years....

Homo Sapiens, modern man, first emerged about 200,000 years ago: http://www.cnn.com/2005/TECH/science/02/16/oldest.humans.ap/index.html. Also, http://www.newscientist.com/article.ns?id=dn7020.

You raised an interesting point when you suggested:

Perhaps there are very few "safe zones" where life can exist long enough to reach the point of becoming intelligent, much less advanced enough to contact other civilizations.

This might be true. But we have many "zones" to explore. Of the 100 or so planets discovered outside our solar system (and there are literally trillions awaiting discovery), all seem to be gas giants orbiting quite near the parent star. Beyond "starquakes," another reason that life and intelligence might be rare is that Jupiter-like planets (gas giants) might most often form close to the parent star and thus block the formation of Earth-like planets in the orbits that allow liquid water. It is thought that liquid water is a necessary precursor for the development life. Maybe there are relatively few safe zones.

 

[theim]

Maybe there is a species somewhere out there dependent on a gas of some kind instead of water? That would be cool.

I do hope no advanced civilization existed within 10 light years of that thing. It would suck to have the Vulcans already wiped out

 

[KarlMarx]

Homo Sapiens, modern man, first emerged about 200,000 years ago: http://www.cnn.com/2005/TECH/science/02/16/oldest.humans.ap/index.html. Also, http://www.newscientist.com/article.ns?id=dn7020.

I stand corrected, perhaps I was thinking that Homo Sapiens did not arrive in Europe until about 35,000 years ago. Up until then, only Neantradahl seems to have been present.

This might be true. But we have many "zones" to explore. Of the 100 or so planets discovered outside our solar system (and there are literally trillions awaiting discovery), all seem to be gas giants orbiting quite near the parent star. Beyond "starquakes," another reason that life and intelligence might be rare is that Jupiter-like planets (gas giants) might most often form close to the parent star and thus block the formation of Earth-like planets in the orbits that allow liquid water. It is thought that liquid water is a necessary precursor for the development life. Maybe there are relatively few safe zones.

I once read that the formation of Jupiter actually helped life to survive on this planet since it attracts comets, asteroids and other objects that otherwise might collide with our planet and wipe out life.

My thinking about safe zones had more to do with black holes, pulsars and other stellar bodies that emit large bursts of lethal radiation and thus would wipe out any existing life on a planet. My thought is that we are sufficiently distant from that type of object that intelligent life had a chance to form on this planet.

 

[sagegirl]

Isnt the universe just full of wonder.......I agree, I thnk we are extremely lucky to be in the safe zone.....a slight misnomer because even a supernova or a similar blast as from this starquake could occur close enough to blast away our atmosphere. We take our existence much too lightly, here we are fighting over god and territory and the like and we have so much to explore and such great opportunities . Such circumstances are probably somewhat rare.

 

[KarlMarx]

Isnt the universe just full of wonder.......I agree, I thnk we are extremely lucky to be in the safe zone.....a slight misnomer because even a supernova or a similar blast as from this starquake could occur close enough to blast away our atmosphere. We take our existence much too lightly, here we are fighting over god and territory and the like and we have so much to explore and such great opportunities . Such circumstances are probably somewhat rare.

Many people think there is no God and that Man is all powerful. Consider that a small comet has more explosive force than all the nuclear weapons on Earth, or that the Sun, an average star among billions, releases more energy in an hour than Man has used throughout history and you have to wonder.....