Exploding Star May Have Damaged Life on Earth

Reedo writes "Scientists have proposed that an ancient supernova may have damaged our ozone layer, wreaking havok on terrestrial life. Previously no one had realized that a cluster of stars could have been so close to the earth during that time. But don't worry about it happening again anytime soon. The next expected supernova is nearly 500,000 light-years away and is too far from the earth to cause any damage."

Effect on evolution?

[cybermage]

Makes you wonder if we're here to discover it happened because it happened.

Plankton, OK, but what else?

[chennes]

They talk about this showing up in the marine fossil record, but what about on land? The article mentions some geological data, but is there any on-land paleontological evidence to support this? Also, they only talk about it killing plankton - does that mean that it was too far away to kill anything larger directly? Perhaps this is why we haven't run across it in any other fossil records...

Time

[radoni]

When exactly *is* 500,000 years? let's say that the next-nearest Nova goes off somewhere in a galaxy far far away. the actual light wouldn't reach for half a million years?

I'm sure this is rocking a dead baby, but how do the "experts" signify exactly *when* things happen, and what specifically that means. Do the anomolies happen and are observed later, the event of which is estimated in reverse?

Does this mean if i put instant coffe in a microwave, i'll go backwards in time?

Cycle of Mass Extinction

[jsse]

Researchers have always worried about there might be in fact a single cause of Mass Extinction [bbc.co.uk]. You can refer to this graph [tulane.edu] for the rough interval of mass extinction.

Most people believe that the meterorite impacts [tulane.edu] is responsible for the mass extinction, but now this new findings may sparks a new way of thinking - the murderer may be someone else.

If we believed that there's a cycle for Mass Extinction, there we don't have much to worry about - as it's still millions of years away. However, some people also believe that the Sixth Extinction [well.com] might come earlier, because human was not present in the last 5 extinction, and that makes the great difference.

Thank you for reading my trolling. I quote as much online reference as possible, but actually my point of view are from the books I read. My apology.

Re:Inane

[Anonymous Coward]

it's not so ludicrous. Stars travel, and millions of years ago there could have been some stars "passing through" and now the remanents of the supernova could be relatively far away. I think their Antares figure is a typo though, isn't our galaxy only 100,000 lightyears across? And besides, no normal star in our galaxy is moving fast enough, relative to us, to cover 500,000 lightyears in only a few million years.

my $.02

Re:Over-reactoring

[lohen]

True, an induced higher rate of mutations does not tend to lead to an increased rate of evolution (unless it be towards radiation tolerance) since the vast majority of mutations are silent or disadvantageous. But this would have influenced evolution nevertheless, simply by killing a load of creatures and creating turmoil in the ecosystem, leading to a period of rapid change and differing evolutionary pressures.

Evolution occurs primarily in response to outside influences of the time, rather than towards any particular goal. Asteroid impacts, volcanic eruptions, and now apparently (although IANA astronomer, and mistrust CNN) supernovae all have a bearing on how things have turned out today.

Pi in yer eye!

[leonbrooks]

Fossils are found things, not theoretical constructs.

True, but you left out a pivotal part of the story: what happened to them and when is a theoretical construct.

Determining their [a]ge depends a lot on physics (through radioactive dating) but only weakly, if at all, on biology.

Now that's just completely wrong. Biologists extracting blood cells from T-Rex bones can get a fairly good idea of an upper limit for the bone's age, based on home much the organic material has decayed. And it's shy at least four noughts of any figure you're likely have in mind. (-:

Of course, when people dig up fresh dinosaur bones, or extract fresh wood from within Manley sandstone, that generally presents them with a pretty big hint about the age of what they've found. But, of course, the false assumptions undergirding this assertion...

The fossil record is "tied to" Darwinian theory only in that the latter is the most successful explanation of the former.

...are so important on philosophical/metaphysical grounds that inconvenient observations like those tend to just get swept under the carpet.

I think the pi in your post is a sign from the gods of science that you're making them do too many beetles, and you need to step outside of your reality bubble for a while so they can discuss things with you. (-:

Re:Inane

[shimmin]

Just because we are in an interesting position in the galaxy now doesn't mean we have been there for any more than a few hundred million years.

Gravitational "mixing" of the galaxy ensures that a star can travel from pretty much any part of the disk to any other part within about a billion years and that our present stellar neighbors were not our neighbors for most of our history.

Basically, we have no clue where in the galactic disk the sun formed, nor which supernova remnant is responsible for seeding the sun's formation, nor the location of most of the nearby objection in the galaxy more than a billion years or so ago.

Supernova danger ranges

[xihr]

Here's [rit.edu] an analysis of the risks associated with nearby supernovae. The executive summary is that gamma rays offer the most potential for destruction, and the danger range is within about 100 ly.