3 ms·

Would it be possible to tell when such events happened far into our past? I'm curious if such an event could trigger a mass extinction [1] on Earth ... and if a

Would it be possible to tell when such events happened far into our past? I'm curious if such an event could trigger a mass extinction [1] on Earth ... and if any of the 5 previous mass-extinctions [2] might coincide with one. [1] http://en.wikipedia.org/wiki/Extinction_event#A_nearby_nova.2C_supernova_or_gamma_ray_burst http://en.wikipedia.org/wiki/Extinction_event#A_nearby_nova.... [2] http://en.wikipedia.org/wiki/Extinction_event#Major_extinction_events http://en.wikipedia.org/wiki/Extinction_event#Major_extincti...

throwaway_yy2Di 12y ago
Probably not from one of these magnetar quakes. The one described in the articled released 10^39 J of x-rays; the typical gamma-ray burst is estimated to be 10^44 J, and moreover, concentrated in a narrow beam. If you're in the path of a GRB, it's looks as bright as a 10^45 - 10^47 J isotropic source. https://en.wikipedia.org/wiki/SGR_1806-20 https://en.wikipedia.org/wiki/SGR_1806-20 https://en.wikipedia.org/wiki/Gamma-ray_burst#Energetics_and_beaming https://en.wikipedia.org/wiki/Gamma-ray_burst#Energetics_and... http://arxiv.org/abs/astro-ph/0102282 http://arxiv.org/abs/astro-ph/0102282 (ref [69] from the previous; page 20 in particular) So, if the article you link to estimates a GRB would be an extinction event within <6,000 light years or so, you could extrapolate that a magnetar quake, 10^7 times weaker, would need to be 10^3.5 times closer, that is, within 2 light years. There's zero magnetars in that range for sure.
- throwaway_yy2Di 12y ago
  Then again, Phil Plait is taking about much lesser effects like damaged satellites. He calculates this could happen at 5,000 light years from a magnetar; that implies (flipping my calculation around) that a GRB could do that all the way from another galaxy (..if it's a "nearby" galaxy).

3 ms·

Would it be possible to tell when such events happened far into our past? I'm curious if such an event could trigger a mass extinction [1] on Earth ... and if a

by BrandonMarc 12y ago

throwaway_yy2Di 12y ago
Probably not from one of these magnetar quakes. The one described in the articled released 10^39 J of x-rays; the typical gamma-ray burst is estimated to be 10^44 J, and moreover, concentrated in a narrow beam. If you're in the path of a GRB, it's looks as bright as a 10^45 - 10^47 J isotropic source. https://en.wikipedia.org/wiki/SGR_1806-20 https://en.wikipedia.org/wiki/SGR_1806-20 https://en.wikipedia.org/wiki/Gamma-ray_burst#Energetics_and_beaming https://en.wikipedia.org/wiki/Gamma-ray_burst#Energetics_and... http://arxiv.org/abs/astro-ph/0102282 http://arxiv.org/abs/astro-ph/0102282 (ref [69] from the previous; page 20 in particular) So, if the article you link to estimates a GRB would be an extinction event within <6,000 light years or so, you could extrapolate that a magnetar quake, 10^7 times weaker, would need to be 10^3.5 times closer, that is, within 2 light years. There's zero magnetars in that range for sure.
- throwaway_yy2Di 12y ago
  Then again, Phil Plait is taking about much lesser effects like damaged satellites. He calculates this could happen at 5,000 light years from a magnetar; that implies (flipping my calculation around) that a GRB could do that all the way from another galaxy (..if it's a "nearby" galaxy).