December 16, 2011
No Supernova Potential In Our Galactic Neighborhood?
A natural supernova close enough to bum our trips is not in the offing.
Given the incredible amounts of energy in a supernova explosion – as much as the sun creates during its entire lifetime – another erroneous doomsday theory is that such an explosion could happen in 2012 and harm life on Earth. However, given the vastness of space and the long times between supernovae, astronomers can say with certainty that there is no threatening star close enough to hurt Earth.
Astronomers estimate that, on average, about one or two supernovae explode each century in our galaxy. But for Earth's ozone layer to experience damage from a supernova, the blast must occur less than 50 light-years away. All of the nearby stars capable of going supernova are much farther than this.
So if a nearby star goes supernova we'll know it is due to an alien attack aimed at wiping out our species. You never can tell what Vogons might rationalize as sensible.
Why we need more space telescopes watching near and distant stars: Look for signs that stars or solar systems are being engineered. Even if a nearby star isn't being tampered with and we do not face a need to burrow underground to survive a period of missing ozone layer we still should find out whether alien species are operating at such scales of engineering that astronomers can detect it.
But we are still free to worry about gamma ray bursts. So we've got that going for us.
A gamma-ray burst could affect Earth in much the same way as a supernova -- and at much greater distance -- but only if its jet is directly pointed our way. Astronomers estimate that a gamma-ray burst could affect Earth from up to 10,000 light-years away with each separated by about 15 million years, on average. So far, the closest burst on record, known as GRB 031203, was 1.3 billion light-years away.
So did the Mayans get a visit from aliens who told them a gamma ray burst was headed our way?
As with impacts, our planet likely has already experienced such events over its long history, but there's no reason to expect a gamma-ray burst in our galaxy to occur in the near future, much less in December 2012.
So if a gamma ray burst hits us in December 2012 that is strong evidence that some aliens have faster-than-light spaceships, rushed ahead of a gamma ray burst from 10,000 light years away, and told the Mayans about it. So in December 2012 we could discover that there's intelligent life out there. How cool is that?
The bigger question is whether there is a black hole roaming in our vicinity.
It need not be very large to threaten our solar system.
The rotation axis of stars is in the same direction as the rotation axis of the Milky Way so it even more unlikely.
ps. don't use light-years. Parsec is the measure of distance within the Milky way
Randal Parker wrote: "So if a gamma ray burst hits us in December 2012 that is strong evidence that some aliens have faster-than-light spaceships, rushed ahead of a gamma ray burst from 10,000 light years away, and told the Mayans about it. So in December 2012 we could discover that there's intelligent life out there. How cool is that?"
No, it's not strong evidence. Even if a gamma ray burst hits us then, the null hypothesis of "the Mayans knew nothing and this is pure coincidence" is more likely, for a host of reasons.
I sincerely hope that this comment was made in jest.
Correcting “anonyq,” the Sun’s rotation axis, at any rate, is in the vicinity of 60° away from the galactic pole; see, for example, this diagram (the Sun’s axial tilt is 7.25° from the ecliptic pole, so the actual difference is somewhere between about 52° and 66°).
Nor are other stars’ rotational axes preferentially aligned; if they were, we could (for example) concentrate our searches for transiting extrasolar planets in a relatively narrow band along the Milky Way.
Further correcting anonyq, back in 2009 there were good images taken of the accretion/dust disk around a Wolf-Raynet star just a few hundred LY away. Our system is looking right down the rotational axis of that highly energetic and unstable star.
Yeah, it's called WR-104 and it's about 8000ly away.
I'm more worried about a mega-volcanic eruption like the one 640,000 years ago in Yellowstone park that buried half of America under several feet of soot and caused a nuclear winter for at least a decade or more and started an ice age.
But heck how often do they happen ? only every 600,000 years on average so Old Faithful is 40,000 years OVERDUE !!
This sounds like a Sirius matter...
"But heck how often do they happen ? only every 600,000 years on average"
Sample size is the problem with that average; we only know of -- what, three? -- super-eruptions from this hot spot. And since the crust moving across the hot spot now ( for any given value of "now") is always going to be slightly different from what moved across it before, we really can't say when the next one would be due.
We have never seen a super volcano erupt. What we do know is that the larger something is the slower it happens. A normal volcanic eruption takes a few months - a super volcano eruption could be in process now and we wouldn't recognize it because it would take years to occur. Certainly if a geologist saw a normal volcano with the crater activity of Yellowstone it would be an event that they would worry about seriously; active geysers, heaving dome, multiple earthquakes, CO2 escapes - none of these are positive indicators that tell us an eruption is 100,000 years away.
I admit I was kidding. Obviously we already know that aliens exist because of all the alien abductions and their intervention in the Cuban Missile Crisis to prevent world thermonuclear war.
PacRim Jim wrote: "The bigger question is whether there is a black hole roaming in our vicinity"
Black holes are just about the last thing we need to worry about. From more than a few black-hole radii away from the event horizon, black holes behave just like any other celestial body. Even a Jupiter-mass black hole would need to pass within a couple AU to significantly affect the Earth's orbit. The likelihood of that in the vastness of space is vanishingly small.
Didn't you see the documentary that was recently released that showed it was the X-Men that stopped the Cuban Missile Crisis? You need to keep up more with historical revisionism.
Aliens created the X-Men.
ROFL... Mr Parker, this is the best thing I've read all day!
I'd long forgotten the 2012 pandemonium. Seriously, bravo. Sarcasm sublime.
It meant to occur but we kept waiting for the beast, well this old article reminds me of a Hollywood movie ‘Noah’ and I think if things going to work in this way as happened in the movie, it’ll be much beneficial.