BBC Focus Magazine

[Lateralman]

I watched on the BBC News recently released NASA images of a planet passing close to its own sun and then having its atmosphere stripped by a solar flare.

Did a solar flare from our own sun cause the KT extinction event? In addition, has this happened many times in the earth’s history?

[M Paul Lloyd]

It is possible that a giant solar flare may have been a partial factor in past extinction events here on Earth Lateralman, but you have to allow for the fact that the Earth has a very good defence against such things in the form of its powerful magnetic field that results from its very special, and active, nickel iron core.
Without it things would be very different indeed on our cozy little home-world.

[Shadowwolf]

I think that such an event is the big killer for the movie Unknown, but as I recall such a scenario was soundly dismissed by those who know the most regards Sol. The planet Lateral mentioned is, however, a bigger gas giant and thirty times closer - that's closer than Mercury is - than we are which makes a profound difference when a flare erupts in its direction.

[Lateralman]

Okay, but we already know that solar flares are powerful enough to knock out our electrical grid.

However, what if any past solar flares we may or may not have experienced were big enough to travel thirty times the distance to reach us, but have not been big enough to strip away our atmosphere? Just big enough to kill all life above ground.

Has there been any research done on this?

Alternatively, is it time to stock up on SPF 50.

[Shadowwolf]

No at this distance a solar flare cannot do what it does in that movie or what it would be like next door to the star as that planet is. A really massive flare these days would be hugely disruptive to our technological society but would have done little to Terra in the distant past as most of the flares power is in charged particles not heat.

Oh and sorry, the film I mentioned above should have been Knowing not Unknown which is a completely different movie.

[M Paul Lloyd]

Ah The Knowing yes, it was ok until the ending which completely ruined it for me.

[Shadowwolf]

As soon as I realised what ET was up to it was effectively ruined in my eyes.

[M Paul Lloyd]

I have to admit it had run quite near the end before I realised what was going on.....

[nemisis1960]

I watched on the BBC News recently released NASA images of a planet passing close to its own sun and then having its atmosphere stripped by a solar flare.

Did a solar flare from our own sun cause the KT extinction event? In addition, has this happened many times in the earth’s history?

i always thought the thinking was that it was an asteroid that struck just of the coast of the gulf of mexico that caused the KT extinction event. Although there is now speculation that it was a combination of the, asteroid and earthquakes volcanic eruptions and a host of natural disasters that caused it.

[M Paul Lloyd]

Yes Nemesis, the Chicxulub impact is now thought to be just one of many factors any two orthree of which the Dinosaurs may have survived, but altogether it probably just proved too much to cope with.