On 27 December 2004 the European Space Agency's Integral Gamma-Ray Observatory was hit by the strongest flux of gamma rays ever measured by any spacecraft. It was the brightest event known to have been sighted on this planet from an origin outside our solar system occurred. Gamma rays from a magnetar 50000 light years from Earth on the far side of our Milky Way galaxy in the constellation of Sagittarius released more energy in one-tenth of a second than our sun has released in the past 100,000 years. It is is thought to be the largest explosion observed by humans in the galaxy since the supernova observed by Johannes Kepler in 1604. A similar blast within 10 light years of earth would destroy the ozone layer. The nearest known magnetar to earth is 13,000 light years distant.
SGR 1806-20 is a magnetar, a particular type of neutron star. It has been identified as a soft gamma repeater with a diameter of no more than 20 kilometres (12 miles) and rotates on its axis every 7.5 seconds. SGR 1806-20 is the most magnetic object ever perceived by mankind, with a magnetic field that is a quadrillion times stronger than that of the Earth.

Gamma-ray bursts in our Milky Way galaxy are indeed rare, but the scientists estimate that at least one nearby likely hit the Earth in the past billion years. Life on Earth is thought to have appeared at least 3.5 billion years ago.

"A gamma-ray burst originating within 6,000 light years from Earth would have a devastating effect on life," said Dr. Adrian Melott of the Department of Physics and Astronomy at the University of Kansas, Lawrence. "We don't know exactly when one came, but we're rather sure it did come -- and left its mark. What's most surprising is that just a 10-second burst can cause years of devastating ozone damage," Melott added.

Within months of its launch, Integral solved a thirty-year-old mystery by showing that the broadband gamma-ray emission observed towards the center of the galaxy was produced by a hundred individual sources. A catalog of close to 500 gamma-ray sources from all over the sky, most of them new, was then complied.

Scientists now know that a rare class of anomalous X-ray pulsars, or neutron stars, also called magnetars, generates magnetic fields a thousand million times stronger than the strongest steady magnetic field achievable in a laboratory on Earth. Neutron stars are extremely dense remnants of exploded stars about the size of Manhattan consisting of tightly packed neutrons.

Neutrons stars rank at or near the top of freaky phenomena found in our Universe. In the early 1930s, California Institute of Technology astrophysicist, Fred Zwicky, an immigrant from Bulgaria, focused his attention on a question that had long troubled astronomers: the appearance of random, unexplained points of light, new stars.

It occurred to Zwicky that if a star collapsed to the sort of density found in the core of atoms, the result would be an unimaginably compacted core: atoms would be crushed together with their electrons squeezed into the nucleus, forming neutrons and a neutron star, with a core so dense that a single spoonful would weigh 200 billion pounds. But there's more, Zwicky concluded: with the collapse of the star there would be huge amounts of leftover energy that would result in a massive explosion, the biggest in the known universe that we called today supernovas.

Most neutron stars house incredibly large magnetic fields. If they are spinning rapidly they make fabulous clocks, cosmic radio beacons we call pulsars. Pulsars can keep time to an accuracy better that one microsecond per year. Some pulsars generate more than 1000 pulses per second, which means that an object with the mass of the Sun packed into an object 10 to 20 kilometers across is rotating over 1000 times per second, or more that half the speed of light!


Integral has seen about 100 of the brightest supermassive black holes, the main producers of gamma radiation in our universe, in other galaxies. But while looking for them in nearby galaxies, surprisingly few have been found. They are either too well-hidden or are only present in the younger galaxies which populate the more distant universe.

Galaxies throughout the universe are believed to be responsible for creating the diffuse background glow of gamma rays, observed over the entire sky. Integral used the Earth as a giant shield to disentangle this faint glow. The data helps understand the origin of the highest energy background radiation and possibly, provide new clues to the history of growth of supermassive black holes since the early epochs of the Universe.

Although not designed to be a gamma-ray-burst ‘watchdog’, scientists realized that Integral could perform this task if assisted by sufficiently powerful software. ESA set a new record for speed and accuracy with the Integral Burst Alert System on 3 December 2003 when a burst was detected, localized and astronomers were alerted in 18 seconds.

The event, called GRB 031203, was faint and close, in cosmological terms, which suggests that an entire population of low energy gamma-ray bursts has so far gone unnoticed.

Integral's gamma-ray vision can peer into the hearts of solar flares, supernovae, neutron stars, black holes, and active galaxies. By exploring the universe at these high energies, scientists can search for new physics, testing theories and performing experiments which are not possible in earth-bound laboratories.

Surveying the entire galaxy looking for the radioactive isotope aluminium 26 with Integral, scientists have been able to calculate that a supernova goes off in our galaxy, once every 50 years.

http://www.dailygalaxy.com/my_weblog/2009/12/december-27-2004-the-most-powerful-space-blast-ever-to-hit-earth-.html

Posted by Casey Kazan, adapted from an ESA release and a release issued by NASA/Goddard Space Flight Center.

coincidentally, the largest tsunami on record hit on Dec 26, 2004...

https://en.wikipedia.org/wiki/2004_Indian_Ocean_earthquake_and_tsunami

Interesting read. I managed to find this information.



The biggest tsunami recorded was 1,720 feet tall and chances are good it will happen again


http://qz.com/193139/the-biggest-tsunami-recorded-was-1720-feet-tall-and-chances-are-good-it-will-happen-again/

http://www.livescience.com/13176-history-biggest-tsunamis-earthquakes.html

Written by
Gwynn Guilford

Obsession
The Sea
March 30, 2014



Fifty years ago this week, the Great Alaska Earthquake ravaged the Pacific Northwest, killing more than 100 people. Nine-tenths of those weren’t caused by the earthquake, though, but by a series of tsunamis that pummeled the coast, one of which towered 219 feet (66 meters) high.






They come taller than that, though. The 1958 tsunami that ripped through Lituya Bay, a sleepy fjord near the Gulf of Alaska, was eight times bigger. And though its causes make it different from the far-traveling waves that slammed Southeast Asia in 2004 or Japan in 2011, the warming of the atmosphere will make both types become more common.





​
Calamity struck at 10pm on July 9, 1958, when a 8.0-Richter-scale earthquake rammed the Alaskan coast up and northward. That impact shook free between 40 million and 60 million cubic yards (30.6 million and 46 million cubic meters) of rock and ice that rimmed the Lituya basin, dumping it 3,000 feet into the bay below. The 1,720-foot monster that reared up as a result shot through the bay at 100 miles per hour (161 kilometers per hour), as Susan Casey details in her book, The Wave: In Pursuit of the Rogues, Freaks and Giants of the Ocean.


Amazingly, four people survived. They were split between one boat that powered directly up the face of the still-building wave, and another that rode it like a surfer about 80 feet above the treetops, until being dumped into the Gulf of Alaska in a hail of uprooted trees.





The 1958 megatsunami scoured Lituya Bay’s mountains bare.(DJ Miller, US Geological Services)
Flanked by ledges of ice and rock—and close to a fault lively enough to dislodge them and cause avalanches—Lituya Bay’s topography is uniquely lethal. Geologists say that a 492-foot wave hit (paywall; pdf, p.155) in 1936, and a 394-footer in 1853. French and Russian explorers met nasty ends there, according to Casey (one christened the middle island “Cenotaph,” which means a monument to the dead.) And then there’s the story Casey retells of a Tlingit Indian woman who returned from a day of berry-picking to find her entire village swept away, the corpses of her clan strewn among the remaining trees.






Most tsunamis in historical record start differently, though. Volcanic rumblings and shifting tectonic plates cause undersea earthquakes. When those quakes force enough land upward, they displace huge ripples of water that grow into tsunamis. The Ring of Fire—the volcanic ridge that curls around the Pacific Ocean—is the planet’s most seismically active, generating 80% of the world’s earthquakes—which is why so many tsunamis slam into Japan and Chile. Landslides, both underwater and above, can create huge waves like Lituya’s; earthquakes are usually, though not always, responsible.





A map of earthquakes and tsunamis from recent history (tsunamis in yellow).(Woods Hole Oceanographic Institute)
A warming climate ups the chance of both types. Melting glaciers redistribute weight across the planet and the related pressure bends the sea floor, increasing volcanic activity.






In fact, that’s what happened at the end of the last ice age, as Casey explains. Though it’s impossible to know exactly how that changed the seas, scientists have some clues—for instance, the undersea landslide off Norway about 7,900 years ago. The resulting tsunamis were only 32-64 feet (pdf). Still, those waves swallowed up a big enough chunk of the coast of the Netherlands, Germany, and Denmark that they helped turn Britain into an island.

yea, but none of those killed 250,000 people... but i think the one to hit the east coast will maybe kill more, when that land mass on the canary Islands slides into the ocean... at least they will have a few hours warning when it does happen...

Global warming isn't helping either water levels are rising .

http://ecowatch.com/2015/05/22/maldives-underwater-climate-change/

It’s not just low-lying island nations either. “A recent study says we can expect the oceans to rise between 2.5 and 6.5 feet (0.8 and 2 meters) by 2100, enough to swamp many of the cities along the U.S. East Coast,” says National Geographic. “More dire estimates, including a complete meltdown of the Greenland ice sheet, push sea level rise to 23 feet (7 meters), enough to submerge London.”



http://qz.com/193139/the-biggest-tsunami-recorded-was-1720-feet-tall-and-chances-are-good-it-will-happen-again/

They come taller than that, though. The 1958 tsunami that ripped through Lituya Bay, a sleepy fjord near the Gulf of Alaska, was eight times bigger. And though its causes make it different from the far-traveling waves that slammed Southeast Asia in 2004 or Japan in 2011, the warming of the atmosphere will make both types become more common.

sorry, i don't believe in the man made global warming idea... i think it's just cycles of weather patterns we've had for the last 2 billion years... and i think we will see an ice age before that happens

When do you think the next ice age will be ? What are your thoughts on holes in the ozone ?

within the next 50 years...the ozone replenishes itself... that gamma ray blast, it took a big chunk of the ozone/upper atmosphere with it when it hit, and we didn't even notice....

unless we are noticing it now...

The article did mention that 10 second bursts does cause ozone damage . I am also reading about Supper Massive black holes from the article ...neat



Integral has seen about 100 of the brightest supermassive black holes, the main producers of gamma radiation in our universe, in other galaxies. But while looking for them in nearby galaxies, surprisingly few have been found. They are either too well-hidden or are only present in the younger galaxies which populate the more distant universe.

you might find this interesting:

http://www.nytimes.com/2015/09/22/science/space/more-evidence-for-coming-black-hole-collision.html?partner=rss&emc=rss&_r=0

Thank you

This part of the article was kind of funny

Every galaxy of note seems to have a supermassive black hole, weighing millions or billions of times as much as the sun, burping sparks of half-eaten stars and gas.