Gamma Ray Burst

[vcf123]

Here is another question that has been bothering me for a while.

I have heard that gamma ray burst from near by object would travel at the speed of light and be undetectable. The earth will be sterilized. I was wondering if we could build a giant shield of some kind on the orbit around earth or the sun to protect us from gamma ray?

Of course, if we have the technology.

Thanks!

[dgavin]

Here is another question that has been bothering me for a while.

I have heard that gamma ray burst from near by object would travel at the speed of light and be undetectable. The earth will be sterilized. I was wondering if we could build a giant shield of some kind on the orbit around earth or the sun to protect us from gamma ray?

Of course, if we have the technology.

Thanks!

Actually, only the half that was facing the GRB would be sterilized. From my understanding the typical GRB only last from seconds, to maybe hours.

If the Moon was on the dark side ( from the GRB's perspective ) enough might be reflected to cause to low doses of radiation, but not planet wide sterilization.

Unless the GRB was at the location of our Sun itself, I don't think it would be possible for enough radiation to push through the entire earth to the dark side from the burst

[NickW]

I think a shield to do something like that could have to encapsulate earth to give us 360 protection from any GRB threats.

[cjameshuff]

I think a shield to do something like that could have to encapsulate earth to give us 360 protection from any GRB threats.

And given the extremely low probability of a GRB occurring close enough and oriented such that Earth is in one of the beams, we'd be better off working on other threats. Really, damage control might be the best route to take...restore the ozone layer as quickly as possible, do something to control the explosion of mold and fungus feeding on dead plant life to keep it from killing injured plants...I think most ocean life would be fine, but might have problems with shallow water plankton, too. All of which is a hell of a lot easier than building a giant shield, doesn't interfere with moonlight or sunlight or blot out the stars, and has application in dealing with other catastrophes and with normal but undesirable events.

[vcf123]

Excellent points. Thank you everybody!!

[slang]

I was wondering if we could build a giant shield of some kind on the orbit around earth or the sun to protect us from gamma ray?

Of course, if we have the technology.

Heh, you answer your own question. If we have the technology, then yes.

[neilzero]

Colonies at the poles of Mercury have a chance of surviving, even if most of Earth's biosphere is sterilized by a radiation event in or near our solar system. This is because the axis of Mercury has essentially zero tilt with respect to the orbit of Mercury. Mercury's orbit is tilted 9 degrees with respect to the plane of Earth's orbit. Mercury is thought to have a very large iron core which would stop all radiation except neutrinos. Neil

[cjameshuff]

Colonies at the poles of Mercury have a chance of surviving, even if most of Earth's biosphere is sterilized by a radiation event in or near our solar system. This is because the axis of Mercury has essentially zero tilt with respect to the orbit of Mercury. Mercury's orbit is tilted 9 degrees with respect to the plane of Earth's orbit. Mercury is thought to have a very large iron core which would stop all radiation except neutrinos. Neil

The axial tilt with respect to the Earth's orbit doesn't mean much...GRBs are unlikely to occur exactly in that plane. A GRB over the horizon from a pole will roast it no matter where it's pointed. Equatorial latitudes are no safer and no more dangerous...you have an even chance of being on the other side of the planet when the radiation hits, no matter where you are. There *is* perhaps a higher probability of a dangerous GRB occurring within the plane of the Milky Way, but that is not at all aligned to Earth's axis or orbit.

If it is an unusual type of GRB that puts out dangerous radiation for more than 24 hours or so, Mercury, Venus, or the moon would have the advantages of low rotation rate...for Earth or Mars, you're best off on the far pole, whichever that is.

Lunar colonies would likely be buried deep for thermal mass (overheating or freezing problems happen slowly, giving more time to correct the issue, and small transients have limited effect) and for radiation shielding, and might be fine even if on the side facing the GRB. Given human paranoia about radiation and the same thermal management reasons, orbital habitats might be coated with enough slag and ice to save their inhabitants. If they do much ore processing, packing ore containers around the habitat seems a simple and obvious way to get more radiation shielding...not as defense against GRBs, just because more radiation shielding is generally better, especially if you don't have to carry it anywhere. Venus...I'd be interested to know how opaque the sky is to gamma at about 50 km altitude in the Venusian atmosphere. Further out...Titan has enough atmosphere to exert a couple atmospheres of pressure even in its tiny gravity well, it'd probabaly give plenty of protection. Especially since it's mostly nitrogen, which I seem to recall reading is the main thing in the way of gamma ray astronomy on Earth. Most other gas giant moon colonies would have the radiation belts of the gas giants to worry about, and would probably be quite well shielded.

[jlhredshift]

Has it happened before during human history?

Maybe

You decide.