Thanks Woody

I have some more info that I didn't incorporate in my presentation, however these or other things could factor in.

Here are some pics of Gamma-rays:
[link to i988.photobucket.com]
[link to i988.photobucket.com]
[link to i988.photobucket.com]

Gamma-Rays
The massive-star model probably does not explain all types of gamma-ray burst. There is strong evidence that some short-duration gamma-ray bursts occur in systems with no star formation and where no massive stars are present, such as galaxy halos and intergalactic space.[53] The favored theory for the origin of most short gamma-ray bursts is the merger of a binary system consisting of two neutron stars. According to this model, the two stars in a binary slowly spiral towards each other due to the release of energy via gravitational radiation, until the neutron stars suddenly rip each other apart due to tidal forces and collapse into a single black hole. The infall of matter into the new black hole in an accretion disk then powers an explosion, similar to the collapsar model. Numerous other models have also been proposed to explain short gamma-ray bursts, including the merger of a neutron star and a black hole, the accretion-induced collapse of a neutron star, or the evaporation of primordial black holes.

A gamma-ray burst in the Milky Way, if close enough to Earth and beamed towards it, could have significant effects on the biosphere. The absorption of radiation in the atmosphere would cause photo dissociation of nitrogen, generating nitric oxide that would act as a catalyst to destroy ozone. According to a 2004 study, a GRB at a distance of about a kiloparsec (3,262 light-years) could destroy up to half of Earth's ozone layer; the direct UV irradiation from the burst combined with additional solar UV radiation passing through the diminished ozone layer could then have potentially significant impacts on the food chain and potentially trigger a mass extinction. The authors estimate that one such burst is expected per billion years, and hypothesize that the Ordovician-Silurian extinction event could have been the result of such a burst, although there is no current evidence to support this idea.

There are strong indications that long gamma-ray bursts preferentially or exclusively occur in regions of low metallicity. Because the Milky Way has been metal-rich since before the Earth formed, this effect may diminish or even eliminate the possibility that a long gamma-ray burst has occurred within the Milky Way within the past billion years.[59] No such metallicity biases are known for short gamma-ray bursts. Thus, depending on their local rate and beaming properties, the possibility for a nearby event to have had a large impact on Earth at some point in geological time may still be significant.

A notable exception is the 5 March event of 1979, an extremely bright burst that was successfully localized to supernova remnant N49 in the Large Magellanic Cloud. This event is now interpreted as a magnetar giant flare, more related to SGR flares than "true" gamma-ray bursts.

[link to en.wikipedia.org]

Other factors:

[link to science.nasa.gov]
[link to istp.gsfc.nasa.gov]

WR 124
[link to i988.photobucket.com]

The gravitational radiation, contributing factor?
[link to i988.photobucket.com]
[link to i988.photobucket.com]

And, the Sun?

The Sun's magnetic poles will remain as they are now, with the north magnetic pole pointing through the Sun's southern hemisphere, until the year 2012 when they will reverse again. This transition happens, as far as we know, at the peak of every 11-year sunspot cycle -- like clockwork.

Earth'’s magnetic field also flips, but with less regularity. Consecutive reversals are spaced 5 thousand years to 50 million years apart. The last reversal happened 740,000 years ago. Some researchers think our planet is overdue for another one, but nobody knows exactly when the next reversal might occur.

Although solar and terrestrial magnetic fields behave differently, they do have something in common: their shape. During solar minimum the Sun's field, like Earth's, resembles that of an iron bar magnet, with great closed loops near the equator and open field lines near the poles. Scientists call such a field a "dipole." The Sun's dipolar field is about as strong as a refrigerator magnet, or 50 gauss (a unit of magnetic intensity). Earth's magnetic field is 100 times weaker.

Below: The Sun's basic magnetic field, like Earth's, resembles that of a bar magnet.

[link to i988.photobucket.com]

[link to science.nasa.gov]



Exploding death star effects earth:
[link to skymania.com]

Youngest black hole:
NASA scientists today reported finding what seems to be the youngest black hole known in our region of the universe. Space telescopes picked up tell-tale signs of the cosmic cannibal’s existence less than 30 years after it was created by a massive stellar explosion.
[link to skymania.com]
[link to en.wikipedia.org]