1000 atomic bombs narrowly miss Earth.
Offline SASKATCHEWAN (CBC) - An asteroid similar in size to an object that exploded above Siberia in 1908 with the force of 1,000 Second World War-era atomic bombs sped past the Earth on Monday, astronomers said Tuesday.
SASKATCHEWAN (CBC) - An asteroid similar in size to an object that exploded above Siberia in 1908 with the force of 1,000 Second World War-era atomic bombs sped past the Earth on Monday, astronomers said Tuesday.
The asteroid, 2009 ND DD45, estimated at 21 to 47 metres across, passed 72,000 kilometres from the Earth at 8:34 a.m. ET, according to NASA's Near Earth Object program.
While 72,000 km may seem a fair distance, it is a fifth of the distance from the Earth to the Moon and about twice as far as the geosynchronous orbits of communications satellites.
The next closest approach of an asteroid in the past week was 2009 DT43, which was about half the size and passed about 390,000 km from Earth on Feb. 26.
The space rock was discovered only two days ago in the sky by Rob McNaught at Siding Spring Observatory in Australia, when it was "a dim speck about 1.5 million kilometres away," the U.S.-based Planetary Society wrote on Tuesday.
At the closest approach, it was over the Pacific Ocean near Tahiti. It could be observed from Australia, Japan, and China, but not from North America or Europe, the Planetary Society said.
The asteroid's size is slightly smaller than the rock that exploded in the atmosphere at an altitude of six to 10 kilometres above the Tunguska region of Siberia in 1908.
That rock, estimated to be about 50 metres in length, sent a blast of heat and a shockwave with a likely energy equivalent of about 10 to 15 megatons of TNT, or about 1,000 times more powerful than the blast from the bomb dropped on Hiroshima during the Second World War.
An estimated 80 million trees covering more than 2,150 square kilometres were flattened, but only two deaths were reported in the sparsely populated region.
The closest listed approach to Earth was a small asteroid designated 2004 FU162, which passed within 6,500 kilometres, or roughly one Earth radius. It was about five to 10 metres in diameter.
Enlightened Atheist, Gaming God.
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Comforting thought for the day:
There could be a planet-shattering rogue comet headed for Earth, right this very moment, and we would never about it until it was just a few weeks away from smashing home because the damn things are completely invisible until they enter the inner solar system and develop their tail.
Isn't astronomy fun?
- Leon Trotsky, Last Will & Testament
February 27, 1940
Comforting thought for the day #2
The probability of comforting thought for the day #1 is very small. Jupiter is our friend.
"Physical reality” isn’t some arbitrary demarcation. It is defined in terms of what we can systematically investigate, directly or not, by means of our senses. It is preposterous to assert that the process of systematic scientific reasoning arbitrarily excludes “non-physical explanations” because the very notion of “non-physical explanation” is contradictory.
-Me
Books about atheism
Comforting thought for the day #3
Space is big. Really, really, fucking, awesomely big.
Just for grins, I pulled an Archimedes and calculated the number of 30 meter rocks that would be needed to fill a sphere one light year in diameter.
I come out to 1.644x10^34.
You could find quite a lot of needles in as many haystacks before a significant earth crossing rock came our way.
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...Why do you have to go and ruin my fun like that?
And where's David Mabus to back me up on how doomed we potentially are when I need him?
- Leon Trotsky, Last Will & Testament
February 27, 1940
Comforting thought #4:
Comets and asteroids are the least of our potential problems. These we can actually do something about, if we start doing certain things like actually watching for them.
Supernova within a certain range, wham. Earth is a cinder. Nothing we can do.
Enlightened Atheist, Gaming God.
Did you take packing efficiency into account? The astroids (assuming they are spherical) will have small gaps between them and their neighbors. Even the best packing methods (such as hexagonal close packed) are only 74% space effecient. The other 26% is the voids between the close packed spheres.
"You say that it is your custom to burn widows. Very well. We also have a custom: when men burn a woman alive, we tie a rope around their necks and we hang them. Build your funeral pyre; beside it, my carpenters will build a gallows. You may follow your custom. And then we will follow ours."
British General Charles Napier while in India
Actually, I did consider packing but I ended up deciding that it really was not relevant to the calculation. I am not needing the total mass or the density for that post, only one very general number. So the rocks could have been cubes for all the difference it would make.
The reason that I chose to make the rocks 30 meters was for simplicity of calculation (the linked article also suggests that the rock was about that size). Basically, 10,000 30 meter rocks of whatever shape will mark off one light second. Then take the number of seconds in half a year to get a radius in 30 meter increments. From there it is just 4/3 pi r^3.
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Comforting thought #5
Supernovae are the least of our worries. Not only is space big but stars are very very far away.
Also, we know what the precursor stars for supernovae are and they are quite rare. The closest one that is likely to pop off in the next few tens of thousands of years is over 150 light years away. At that range, it will probably be a bit brighter than the moon for several days but that is about all that it will do.
If there was one in the range of 10 to 20 light years out, that would probably produce enough nitrogen compounds in the upper atmosphere to take out about half the ozone layer. That would be bad but it would not destroy all life on earth. Possibly more than half the life on earth would die from the resulting glaciation but life in general would probably survive.
Sirius B might have the potential to become a type 1A supernova (that is the cool kind that can outshine a galaxy for several days) and it is only about 8 light years away. However, for that to happen, Sirius A will have to first enter the red giant phase and that is not estimated to happen for about 900,000,000 years. By that time, we will have been run completely around the center of the galaxy about 450 times, so slim odds that we will be anywhere nearby.
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You're no fun. Alrighty then.
Comforting thought #6:
A black hole could whiz by sucking us all into nothingness. Granted, it would have to be pretty far off for us to not see it's effects at the moment, but there could be one heading in our direction to take us out in a decade or five.
Enlightened Atheist, Gaming God.
Dude, science is fun.
Comforting thought #7
There is a multi million stellar mass black hole in the center of our galaxy.
7a. It is less dense than water.
7b. If you had a spaceship that could go there, you could get less than a meter from the event horizon and nothing special would happen.
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Imagine how many of these potential hassards we could spot if we spent nothing on religious politics or nationalism, and spent that money on more telescopes.
We are never going to prevent a caticlism, it will happen eventually. BUT to think that we could at least put off the inevitable for a while, but are squandering our time on selfish tribalism is sickening.
No, humanity is more intrested in the short term alpha male mentality. I may sound like a pessimist but I am postitive that if humanity pulls it's collective head out of it's ass, we don't have to jump off the cliff of selfishness. I am just not sure if it will.
"We are a nation of Christians and Muslims, Jews and Hindus -- and nonbelievers."Obama
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