Gamma Ray Burst
The threat level from a gamma ray burst is low due to the low chance of one occurring in our galaxy. It would also have to be aimed straight at us.
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Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions in distant galaxies.
They are the most luminous electromagnetic events occurring in the universe.
Bursts can last from milliseconds to nearly an hour, although a typical burst lasts a few seconds.
The initial burst is usually followed by a longer-lived "afterglow" emitting at longer wavelengths (X-ray, ultraviolet, optical, infrared, and radio)
This creates two, oppositely shining beams of radiation shaped like narrow cones.
Planets not lying in these cones would be comparatively safe; the chief worry is for those that do.
GRB's can cause the following:
Deadly radiation levels
Chemical damage to the stratosphere
Depleted ozone
Mass extinction
Protect yourself
Nothing to do but hope you never get hit by one.
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Gamma-ray bursts (GRBs) are flashes of gamma rays associated with extremely energetic explosions in distant galaxies.
They are the most luminous electromagnetic events occurring in the universe.
Bursts can last from milliseconds to nearly an hour, although a typical burst lasts a few seconds.
The initial burst is usually followed by a longer-lived "afterglow" emitting at longer wavelengths (X-ray, ultraviolet, optical, infrared, and radio)
All the bursts astronomers have recorded so far have come from
distant galaxies and have been harmless to Earth, but if one occurred
within our galaxy and were aimed straight at us, the effects could be
devastating.
Currently orbiting satellites detect an average of about
one gamma-ray burst per day.
Measuring the exact rate is difficult, but for a galaxy of approximately the same size as the Milky Way,
the expected rate (for long GRBs) is about one burst every 100,000 to
1,000,000 years.
Only a small percentage of these would be beamed
towards Earth.
Estimates of rates of short GRBs are even more uncertain
because of the unknown degree of collimation, but are probably
comparable.
This creates two, oppositely shining beams of radiation shaped like narrow cones.
Planets not lying in these cones would be comparatively safe; the chief worry is for those that do.
GRB's can cause the following:
Deadly radiation levels
Chemical damage to the stratosphere
Depleted ozone
Mass extinction
Protect yourself
Nothing to do but hope you never get hit by one.
Swift GRB highlights
NASA's Swift satellite has given astronomers more than they could have hoped for. Its discoveries range from a nearby nascent supernova to a blast so far away that it happened when our universe was only 5 percent of its present age.
April 13, 2010: NASA's Swift discovers its 500th burst. GRB 100413B is a long burst in the constellation Cassiopeia.
April 23, 2009: GRB 090423 in Leo holds the record for the farthest burst yet known -- 13.04 billion light-years away. "The burst is beyond the farthest confirmed galaxies and quasars, making it the most distant object we know in the universe today," Fox said. This find validates models suggesting that galaxy and star formation were well under way in the universe's first billion years and that some early stars died as bursts.
March 19, 2008: GRB 080319B, in Boötes, is truly extraordinary. It produces enough light to be seen briefly with the unaided eye, cresting at visual magnitude 5.3 despite occurring 7.5 billion light-years away -- or more than halfway across the visible universe. Scientists conclude that one of its particle jets appears to have been aimed squarely at Earth.
July 14, 2007: GRB 070714B explodes in Taurus. Afterglow observations indicate a distance of 7.3 billion light-years, making this one of the farthest short bursts to date.
Feb. 18, 2006: GRB 060218 explodes in Aries 450 million light-years away -- in our back yard, cosmically speaking. Although faint, the burst emits detectable gamma rays for more than 40 minutes and detectable optical and X-ray emission lasts more than 10 days. The event is a hybrid, showing characteristics of both a GRB and a supernova, and leads to the best observations yet exploring connections between these phenomena.
Sept. 4, 2005: At a distance of 12.77 billion light-years, GRB 050904, located in Pisces, is the farthest-known GRB at the time, the first of many such Swift records.
May 9, 2005: GRB 050509B, in Coma Berenices, erupts with a flash of gamma-rays that lasts just 0.03 second. Swift turns to the burst fast enough to detect 11 X-ray photons, making this the first short burst with a detected afterglow.
Dec. 17, 2004: Swift's first burst, in Crater, is eight-second-long GRB 041217.
NASA's Swift satellite has given astronomers more than they could have hoped for. Its discoveries range from a nearby nascent supernova to a blast so far away that it happened when our universe was only 5 percent of its present age.
April 13, 2010: NASA's Swift discovers its 500th burst. GRB 100413B is a long burst in the constellation Cassiopeia.
April 23, 2009: GRB 090423 in Leo holds the record for the farthest burst yet known -- 13.04 billion light-years away. "The burst is beyond the farthest confirmed galaxies and quasars, making it the most distant object we know in the universe today," Fox said. This find validates models suggesting that galaxy and star formation were well under way in the universe's first billion years and that some early stars died as bursts.
March 19, 2008: GRB 080319B, in Boötes, is truly extraordinary. It produces enough light to be seen briefly with the unaided eye, cresting at visual magnitude 5.3 despite occurring 7.5 billion light-years away -- or more than halfway across the visible universe. Scientists conclude that one of its particle jets appears to have been aimed squarely at Earth.
July 14, 2007: GRB 070714B explodes in Taurus. Afterglow observations indicate a distance of 7.3 billion light-years, making this one of the farthest short bursts to date.
Feb. 18, 2006: GRB 060218 explodes in Aries 450 million light-years away -- in our back yard, cosmically speaking. Although faint, the burst emits detectable gamma rays for more than 40 minutes and detectable optical and X-ray emission lasts more than 10 days. The event is a hybrid, showing characteristics of both a GRB and a supernova, and leads to the best observations yet exploring connections between these phenomena.
Sept. 4, 2005: At a distance of 12.77 billion light-years, GRB 050904, located in Pisces, is the farthest-known GRB at the time, the first of many such Swift records.
May 9, 2005: GRB 050509B, in Coma Berenices, erupts with a flash of gamma-rays that lasts just 0.03 second. Swift turns to the burst fast enough to detect 11 X-ray photons, making this the first short burst with a detected afterglow.
Dec. 17, 2004: Swift's first burst, in Crater, is eight-second-long GRB 041217.
