Universe's most powerful blast ever seen witnessed this week
A gamma ray burst that occurred 7.5 billion years ago was visible on Earth by the naked eye this week. It was "2.5 million times brighter than the most powerful supernova ever seen."
Here's a History Channel video about Gamma ray bursts. "Scientists at the University of Kansas believe gamma ray bursts were responsible for a great mass extinction on Earth 450 million years ago. The gamma rays strip away the ozone layer and generates a chemical smog, producing a widespread chill that grips the globe. Every few seconds, a supernova emits jets of deadly gamma rays somewhere in the galaxy. If one of these gamma ray bursts should happen sufficiently close to the solar system, all life would perish."
From Wikipedia:
Research has been conducted to investigate the consequences of Earth being hit by a beam of gamma rays from a nearby (about 500 light years) gamma ray burst. This is motivated by the efforts to explain mass extinctions on Earth and estimate the probability of extraterrestrial life. A gamma ray burst at 6000 light years would result in mass extinction; a 1000 light year distant burst would be equivalent to a 100,000 megaton nuclear explosion. A burst 100 light years away would blow away the atmosphere, create tidal waves, and start to melt the surface of the earth. There is a one in a million chance that there could be a gamma ray burst as near as the earth's closest star, Alpha Centauri, in the lifetime of the earth. Such a burst, at 4.3 lightyears distant, would effectively incinerate the earth.Link
the latest
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Don't forget to put the SP50 on your nose and the tops of your ears.
But will the super Russian cockroaches survive?
If a GRB came along the far side of the sun, would we survive?
But I thought gamma rays would just make me big, green and angry. Who knew?
MythBusters found fruit flies to be more hardy than cockroaches in regards to radiation exposure.
The 'alpha centauri' scenario cited in Wikipedia is brought to you courtesy of that great font of scientific wisdom, the History Channel.
Greg Egan wrote a great story about this sort of this. I think it was Diaspora. I'm wondering if this was a result of several super massive black holes coming together?
We're really only just beginning to understand (barely) the mechanics and parameters behind massive GRBs . I wonder how much GRBs should factor into the Drake equation - which is an unsettling question to ask. It may be that Galaxies are actually hostile to the formation of life (at least the long term evolution) and intelligence.
As far as frying the earth is concerned, depends on how close to the earth the gamma ray burst is. One that is say, 8,000 light years away would only damage the ozone layer - 20% or so.
Sure...we'll all die, but life would probably continue on the earth in some form. Tardigrades perhaps.
My point is, doesn't have to be 8 light years away to kill us all. And in fact, researchers have found the beginings of a Hypernova just far enough away, angled at just the right amount to do just that.
I, for one, welcome our new electromagnetic overlords.
In other news, scientists have discovered that the star Alpha-Centauri has a massive solar flare that appears to spell "Psycho".
Neighboring stars have spewed their Oolong tea in alarm and ordered the staff to bring in the lawn furniture and close the shutters, quickly now before the children see.
I saw that Myth Busters episode, which I thought was really good. They did nuke cockroaches but did not conduct tests on the super Russian cockroaches bred in space.
http://www.boingboing.net/2008/01/21/super-cockroaches-co.html
These überoaches may be the harbingers of the electromagnetic overlords
And people are worried about the economy. Silly Humans.
Sweet! Break out the Purple Pants!
Damn!
Well, Jane, it just goes to show you, it's always something.
What, again?
Technogirl said, "It may be that Galaxies are actually hostile to the formation of life (at least the long term evolution) and intelligence."
I think we could have 99% of the galaxies devoid of life, and there would still be lots left. I see nothing wroing with being 1% hopfule when that 1% represents billions of galaxies, and trillions of stars. Or, maybe we're it and the whole place is ours.
"A gamma ray burst at 6000 light years would result in mass extinction; a 1000 light year distant burst would be equivalent to a 100,000 megaton nuclear explosion. A burst 100 light years away would blow away the atmosphere, create tidal waves, and start to melt the surface of the earth."
And one 10 light years away would finish the job, and no doubt one 1 light year away would be even vaporize the vapor. Presumably, one around the orbit of Pluto would leave one hell of an afterimage. Yawn. While all these things may be technically true, all observed GRB's are *extragalactic*. Once per galaxy per 100,000 years are pretty good odds by my book, not to mention the volume of space in our galaxy (150,000 ly across, give or take) suggest it's unlikely that one could pop up next to us. Not to mention that a "1/1,000,000 event PER 10 billion years" (the whole lifetime of the earth thing) is probably on the order of magnitude of the probability of all of the hydrogen in the ocean spontaneously undergoing fusion. If a GRB suddenly creeps up on us at a mere 10 ly away, it's time to just acknowledge that God hates us.
"Scientists at the University of Kansas believe gamma ray bursts were responsible for a great mass extinction on Earth 450 million years ago"
And the creation of the Incredible Hulk!
Mike
~who thinks the Hulk needs to be referenced more in this post.~
While all these things may be technically true, all observed GRB's are *extragalactic*. Once per galaxy per 100,000 years are pretty good odds by my book, not to mention the volume of space in our galaxy (150,000 ly across, give or take) suggest it's unlikely that one could pop up next to us.
Ari1413@17:
So, let's do the math.
Assume the following:
(1) All GRBs outside 6K ly are of no interest. (A conservative assumption, but easily fungible.)
(2) The Milky Way is essentially a circle of radius 75K ly.
So _if_ a GRB goes off in the Milky Way, the probability of it being within 6K ly are 6^2/75^2 = .0064, i..e., 0.64%.
Sure, "mass extinction" isn't as bad as "incineration of the planet", but, you know, it's bad enough. :)
That is to say: there's a decent chance that we'll only ever see one GRB in the Milky Way...not because they're uncommon (although they appear to be), but because one might be enough to ensure that we (as a species) wouldn't be around to see another.
"There is a one in a million chance that there could be a gamma ray burst as near as the earth's closest star, Alpha Centauri, in the lifetime of the earth."
First Pluto's not a planet now the Sun's not a star?
Wow! Edward Teller once gave a lecture on gamma ray bursts in space at Argonne National Laboratory and it was so interesting that nobody asked about his work with the Manhattan Project. Even HE was freaked out - he asked "Doesn't anybody here want to ask about my work on the first atomic bomb?"
Hahahaha!
"Astronomers have placed the star in the constellation Boötes. They have estimated it to be 7.5 billion light years away from Earth, meaning the explosion took place when the universe was less than half its current age and before Earth formed."
Since their headline focuses on "Most Distant Object Visible to Naked Eye" it would've been nice for the Space.com article to provide a star chart so we could actually try and see it with our naked eyes. I'm not all knowledgeable about constellations, but some quick Googling finds that Bootes is off the handle of the Big Dipper. I'll have to give it a look-see, though I'm sure it appears as nothing more than another point of light to the amateur astronomer.
"Anybody not wearing 2 million sunblock is gonna have a really bad day, GET IT??"
-- Linda Hamilton as "Sarah Connor" in Terminator 2: Judgment Day
isnt anyone else sh*t scared about this =(
Jrtom:
Doh! Tried to recall from memory and got the diameter wrong by a factor of 2.
I'm not sure where wikipedia got its number, but it gives it at 100k ly, fwiw. But also, it mentions a 1000 ly thickness, which gives a little wiggle room for the 6000 ly, since a sphere centered on us occupies (albeit slightly) less percentage volume than does a circle of the same diameter in 2D. Still, even with your numbers, .64 percent is pretty low probablity for an event that happens every 100,000 years. I'd disagree with you and say that this means there's a 99+% chance that if we're "lucky" enough to see one of these things in our galaxy, it'll be at some safe range.
And that's a mass extiction event, rather than a boil-the-oceans event, which has odds far lower. Not to mention that for what its worth, if some supergiant were to GRB 10 ly from us, we'd have hundreds of thousands of years to actually see the star coming - a big supergiant at 100 ly would be pretty noticable, all the more so if it were moving rapidly relative to the sun (it would have either a large proper motion or doppler shift). I'm not sure what you can do about something like this, but with a few thousand years warning, I'm sure someone could think of something.
On the other hand, this got me thinking about the whole "lifetime of the earth" thing. 0.9936 ^ 100 (the odds that we'd be hit over the last 10 million years) is about 50%. 0.9936 ^ 1000 (100 million years) = 99.998% chance of being hit, which either makes us pretty damn lucky (since nobody's hypothesizing a GRB extinction in the last 100 my), or it means somewhere the math is wrong.
One thing I've been thinking about is the whole collimation thing. Not only does a GRB have to go off in the right place, but it also has to be pointed in the right direction, since the burst is a jet, not a sphere. I actually tried to look up the distribution of stellar axis of rotations relative to the plane of the galaxy, but couldn't find anything. Otoh, *our* solar system's ecliptic is tilted 60 degrees relative to the plane of the galaxy, which probably means that unless the solar system's special in some way, that the distributions are random. Given that the jets are 2-20 degrees across, this means that there's a max of 20^2/180^2 *2 (the area taken up by 2 jets in the sky, if my math is right) chance (around 2%) that any burst would intercept us, regardless of its distance. When you multiply all that up, you get a ~12% chance of a "hit" every 100 my, which is about right, I guess.
Of course, none of this takes away from the most important issue: seen with naked from 7 bly away = COOL! :)
A close GRB would be very destructive, certainly, but 'effectively incinerate the earth' is debatable.
Causing most plant life to catch on fire, yeah, that's easy, the Chixulub impact most likely did that. Complete vapourization, no chance. As Dutch has pointed out, if the Sun were to go supernova the Earth's surface would ablate at hundreds of metres per second, leading to vapourization on a timescale of days.
GRBs simply don't last that long, and a 2.5 millionfold scale-up still wouldn't let it vapourize the Earth in the times they last unless it were closer to us than the Sun is now.
A GRB close by( somewhere in the galaxy )could certainly have the potential to spoil ones day. I think though, if you want to keep yourself up at nights, Eta Carinae, has a higher probability of spectacularly crashing and burning our civilization ( such as it is). More here:
http://en.wikipedia.org/wiki/Eta_Carinae
Seems that it is ~ 7000 lys near and has a bad case of indigestion.
Kurtmac (#22):
Since their headline focuses on "Most Distant Object Visible to Naked Eye" it would've been nice for the Space.com article to provide a star chart so we could actually try and see it with our naked eyes
It only flared for about an hour, so, if you go looking at Bootes for it, you're not going to see it.
In that respect, the Triangulum Galaxy at 2.9 million lightyears away still holds "farthest visible object that you might actually be able to see." And you'd need a clear night and dark skies and it'd still be hard to spot.
The Andromeda Galaxy at 2.5 million lightyears away is the farthest object that you can really see with any regularity (put it this way; the one they knew about before telescopes).