Linking Mass Extinctions To the Sun's Journey In the Milky Way

schwit1 writes "In a paper published today on the Los Alamos astro-ph preprint service, astronomers propose that as many as eleven past extinction events can be linked to the Sun's passage through the spiral arms of the Milky Way. (You can download the paper here [pdf].) From the paper: 'A correlation was found between the times at which the Sun crosses the spiral arms and six known mass extinction events. Furthermore, we identify five additional historical mass extinction events that might be explained by the motion of the Sun around our Galaxy. These five additional significant drops in marine genera that we find include significant reductions in diversity at 415, 322, 300, 145 and 33 Myr ago. Our simulations indicate that the Sun has spent ~60% of its time passing through our Galaxy's various spiral arms.'"

Comments

Oort cloud?

[Anonymous Coward]

I only read the abstract, but while it proposes a correlation it did not speculate on the exact cause of the extinction. I wonder if passing 'nearer' (I use the term loosely) to higher concentrations of stars might disturb the Oort cloud, sending more comets than normal careening in towards the inner solar system ... or if we might catch stragglers from other stars' own Oort Clouds.

Re:Rubish

[Anonymous Coward]

It means every time a mass extinction occurs on Earth, a galactic spiral arm is contructed.

Re:suuuure

[icebike]

in other news...many people die in hospitals, therefore hospitals may cause death.

And indeed they do.

http://www.health-care-reform.net/causedeath.htm
http://en.wikipedia.org/wiki/Hospital-acquired_infection

So don't be so quick to dismiss the possibility of causation, simply because it was discovered by correlation.
Falsely assuming no-causation is every bit as much as a statistics induced error as falsely assuming causation.

With correlation you have a reason to look for causation. Without correlation, looking for causation is just shooting in the dark.

Re:Rubish

[hairyfeet]

Well I'm not a scientist but with a little common sense being applied and knowing what we know it makes sense. After all what do we know so far? Well we know there is this HUGE band of rock at the outer edge of our system called the Oort Cloud, there is also another huge band of rocks in the inner system which may have been a failed planet. If going through the arm caused changes to the gravitational fields way out there in the oort cloud it probably wouldn't take much to get one of those chunks moving, after all that is where it is believed all our long term comets came from so there had to be something in the past that got the comets going. So if you look at how big a period we are looking at and how much debris we have in the inner belt the idea that going through the arm may occasionally cause one of those big inner rocks to get flung at us,possibly by being hit by something fling out of the oort? Really doesn't sound too implausible to me.

To me the thing I find really interesting is how many times our friend Mr Jupiter has saved us by being a big giant garbage collector and pulling all this crap into it that could have easily headed our way if it wasn't there. i honestly wouldn't be surprised if it turned out for every extinction event there was probably thousands that didn't happen because Jupiter sucked it up or slung it off in another direction,given how many times we have seen impacts in just the little bit of time we've been able to see that far out.

So I wish them all the luck, maybe if we can find out exactly what events cause these maybe we can avoid it happening to us, as while I doubt we'd see 100% fatalities of the human race one really nasty impact could easily send us back to the dark ages.