back to article Earth escapes obliteration by comet

NASA has released another statement on Comet Elenin, the totally insignificant comet it keeps giving out statements about, to say that it has broken up into "smaller, even less significant, chunks of dust and ice". "This trail of piffling particles will remain on the same path as the original comet, completing its unexceptional …

COMMENTS

This topic is closed for new posts.

Page:

Joke

Humor Optional

". . . my subcompact automobile exerts a greater gravitational influence on Earth than the comet . . . "

We must destroy his car before it destroys the world!

13
0
Alert

OMG!

He has a car with a black hole in it?

0
0

haha, I saw that movie. 2/10

1
0
Silver badge
Alert

New headline

"The scientific reality is this modest-sized icy dirtball's influence upon our planet is so incredibly minuscule that my subcompact automobile exerts a greater gravitational influence on Earth than the comet ever would."

"Don Yeomans' car set to DESTROY THE EARTH!"

2
0
Silver badge
Mushroom

> I cannot begin to guess why this little comet became such a big internet sensation

It's because a lot of the noisiest people on the internet are idiots.

18
0
Anonymous Coward

Fight fire with fire

NASA have to speak to these people on their terms:

"Stupid Internet rumour is stupid"

Then it might sink in.

4
0
Bronze badge

It became a sensation because somebody started the ball rolling and NASA issued a denial. As far as conspiracy theorists are concerned, if somebody connected with the government denies something then that means it must be a cover up. Had NASA simply ignored the idiot rumours they would have fizzled out after a couple of days.

1
0
Bronze badge

"I cannot begin to guess..."

"I cannot begin to guess why this little comet became such a big internet sensation"

I'm happy to make a guess: too many people are too fucking stupid.

9
0
Def
Bronze badge

""I cannot begin to guess why this little comet became such a big internet sensation," Don Yeomans of NASA's Near-Earth Object Programme Office at the Jet Propulsion Laboratory..."

The fact that it's coming out of JPL might have something to do with it. They don't exactly have a pristine record when it comes to space exploration.

0
7
Facepalm

OMG we're all going to die....

That means the comet was only 3.8 billion double decker buses away! That's almost in my back yard!

1
0
Joke

@"the comet was only 3.8 billion double decker buses away!"

Yeah but its an old rock, so it has an OAP bus pass to travel where it likes.

1
0
Silver badge

Standard units please

I believe the correct unit for things of that size is the Wales rather than the bus. Could somone please correct this figure?

0
0
Bronze badge

Sorry no. Areas are measured in Waleses. Distances should be measured in Gootball Pitches, heights in Nelsons Columns and volumes in Swimming Pools (Olympic). As an alternative to any of those last three you could always use the universal constant that is the Jumbo Jet.

0
0
Bronze badge

Yeah NASA, but...

I think we'd better send Bruce Willis up anyway, just in case.

2
0
Silver badge
Facepalm

They already did

Why else do you think its in bits?

1
0
Joke

...actually, not such a bad idea.

I have a whole list of untalented loudmouthed and ignorant celebrities that should be drafted for a one-way mission to save the earth.

They kill the comet and don't come back, we win.

They don't kill the comet and don't come back, we win.

They miss the comet entirely and don't come back, WE STILL WIN!

There seems to be a pattern here...

5
0

Yeah and it's been a while since he showed up on Letterman too.

0
0
Bronze badge

Except for one scenario

They make a film about it, we lose. Fuck.

1
0
Mushroom

... better idea...

Rather than send loudmouthed and ignorant celebrities, we should reinstate the draft and send all the Republican candidates for President and their "job creators" on a mission to save Earth...

They kill the comet and don't come back, we win.

They don't kill the comet and don't come back, we win.

They miss the comet entirely and don't come back, WE STILL WIN!

And we wouldn't have to cut their taxes...

0
1
Bronze badge
Thumb Up

OhMyGodWe'reAllGoingTo... er... not die? Oh. Spiffy!

2
0
WTF?

"... most pose no threat to Earth"

MOST? How comforting.

Seems to me that it only takes ONE to really ruin my day, if that ONE decides to pay the planet a visit with a direct hit.

0
0
Coat

Poorly educated NASA boffins

"I cannot begin to guess why this little comet became such a big internet sensation," - Don Yeomans of NASA's Near-Earth Object Programme

What kinda scientist is he?

Has he never heard of the inverse proportionality rule of triviality and the web

2
0
Silver badge

One big bullet, or a shotgun blast?

Remember, kiddies, F=MA ... It doesn't matter how many chunks you cut it into, the mass and vector remains the same. If it hits the Earth, the total energy transfer will also be the same. Think about it.

0
9

correct

but many smaller objects have mugh greater surface area and thus experience much greater drag. More of the energy will be dissapated in the atmosphere. Which if I had to choose I would rather it be. that or a large sparcly populated desert area. or Las Vegas.. that would be fine too.

1
0
Silver badge

Thinking...

What is your bullet-proof vest (atmosphere) is more likely to stop - a big bullet or a bunch of shotgun pellets?

0
0

"Remember, kiddies, F=MA ... It doesn't matter how many chunks you cut it into, the mass and vector remains the same. If it hits the Earth, the total energy transfer will also be the same. Think about it."

While true, the increased surface area means much more will burn up in the atmosphere.

0
0
Anonymous Coward

Except you forgot the relationship between surface area, mass and how things burn up in the atmosphere.

1
0
Bronze badge

yeah, but....

if it were lots of smaller pieces, they would stand a better chance of burning up on entry. Also, the 'total energy transfer' would be spread out over a much larger area (unless it was cut into chunks that didn't drift apart, at all) instead of all of it hitting in exactly the same place.

0
0

I did think about it. The atmosphere means that a single large chunk with a mass of, for example, 100 tonnes, stands a much greater chance of reaching the ground with some intact mass than any one of 100 chunks each weighing 1 tonne do.

0
0

Errr....

It missed already!

1
0

re:One big bullet, or a shotgun blast?

Indeed, the total energy transfer will be approximately the same. However because the chunks have a much larger total surface area, they will experience far more drag in the upper atmosphere and because they have a much smaller volume each compared to their surface area, will experience more severe and deeper heating.

So while the planet will receive the same amount of energy total, most of that energy will be wasted into the upper atmosphere as the chunks burn up instead of falling to the ground and killing people.

1 big rock == 1 big crater, lots of dust, dead people, etc.

hundreds of small rocks == Most burn up on entry, those that don't burn up completely leave a few small craters scattered across the landscape. Some people might get unlucky and get hurt in the process.

0
0
Anonymous Coward

RE: One big bullet, or a shotgun blast

OTOH the surface area increases, and with it friction, which means that there is a high chance that if it enters the atmosphere it will burn up easier.

0
0
Vic
Silver badge

> It doesn't matter how many chunks you cut it into, the mass and vector remains the same.

But the surface area increases dramatically.

> If it hits the Earth, the total energy transfer will also be the same.

Only if it all hits the Earth.

Because of the increased surface area, far more of an inbound object would burn up in the atmosphere. The energy will be dissipated as light and heat, rather than transferred into the planet.

So although you are right in that the total amount of energy entering the atmosphere will be the same, you are wrong in thinking that the same amount of energy will transfer to the Earth.

Vic.

0
0
Anonymous Coward

Thought about it.

The total surface area of the mass will vastly increase after a breakup which will affect any heat transfer and melt the ice ball far more quickly.

Bits bouncing off each other due to outgassing may deflect some of them off their normal path.

Of the bits that don't melt, the variously sized/massed bits will be affected differently by air resistance in the outer atmosphere, slowing each at a different rate. This will spread the total mass out over a longer trail which will impact the lower atmosphere over a longer period of time resulting in a lower total rate of energy transfer.

0
0

Energy divided by cubic meter is Power Density

Energy is Mass times speed of light squared.

Break up the mass into a larger space (bits spread apart by the breakup) you then have a lower power density.

Yes the same amount of energy is converted (can't create or destroy energy but only convert it in form) but is spread out over larger area.

0
1

The atmosphere I'm breathing right now? You want the big comet to burn up in that atmosphere?

You don't think there may be a little problem with the sky catching fire, for those of us underneath it? Which, what with the jetstream and all, is probably everybody.

You know, 65 million years before present, mostly buried underground, is a single thin worldwide layer of space-deposited iridium... and soot. The world burned.

Fortunately, less so this week. The rate at which space rock continually falls onto Earth is fairly steady. When we go through a comet's orbit it gets noisy...

0
0
Silver badge

Not to mention the secondary and tertiary factors.

The break up means the pieces are now on different orbits. Some of those pieces will now be sucked up by other planets. And of the ones that get past the other planets, some of those will miss the earth completely.

0
0
Mushroom

Energy Transfer

Force doesn't equal the amount of energy to be dissapated by the comet striking the earth, so the equation of F=MA is irrelevant. The equation to use is E=MC (squared).

You have to calculate the total energy to be converted from on form to another (Kinetic energy of the comet to heat). Then if you spread that energy across many smaller pieces you now have a much larger surface area for friction to act on the bodies spread out over larger area of the planet, so then the "power density" or amount of energy per cubic meter is now decreased as well.

Meaning lesser impact over the wider area of the event.

0
3
Bronze badge

It's all irrelevant anyway. The comet was never going to hit the earth. So it matters not whether it broke up.

0
0
Silver badge

"The equation to use is E=MC (squared)."

Please don't post on issues you clearly can't understand

1
0
Mushroom

The 50 megaton Tsar Bomba set off over London would make for a bad day.

The sun hits the earth with roughly the same amount of energy every second.

Its not how much energy that matters, its what it ends up doing.

0
0
Bronze badge

Unless, of course...

...only PART of the cloud of bits hits the earth while the other part skims on by, instead of the whole mass hitting in central impact...

...or the moon happens to be in position to block part of the debris cloud (Sure, it's unllkely -- but so is a comet colliding with the Earth!)...

...or if the smaller bits have time to vaporize in atmosphere before impact...

...or... or... or...

0
0
Silver badge

@easyk (and others)

Greater drag, perhaps.

But a mountain-sized lump of ice and rock entering the Earth's comparatively shallow "gas cushion" will certainly tunnel through to make land-fall, regardless. It would create a really, really narsty mess.

I'm amused by all the folks who fail to understand the scale of this kind of event (which WILL happen, hopefully not in my lifetime).

0
1
Silver badge

Hah!

Shame on you unbelievers. The world ended a few days ago, we are now figments of our own nightmares, living in purgatory, the matrix or whatever half-brained the "world is ending on XXX date" come up with to excuse their insanity this time.

0
0
Anonymous Coward

how does

a comet just randomly, after probably millions of years going round in circles, just randomly break up into loads of smaller chunks? can anyone enlighten me?

0
0
Bronze badge

Take a handful of rocks...

...and pack them into a snowball. This is your average comet.

The tail of a comet is mainly snow and water vapor that is boiled off as your dirty snowball passes near the sun. When the comet leaves the inner solar system and heads back into the up-and-out, it re-freezes.

Eventually two things can happen -- either there is not enough snow and ice left to hold everything together as it passes the sun and things start scattering due to light pressure and gravitational perturbations, or a particularly large and juicy pocket of ice in the center of the mass boils off more quickly than the resulting vapor can escape and blows the thing apart.

NB: IANAA, but the above is my understanding of the processes.

1
0
Silver badge

Your processes are good

but your snowball model is a bit old. Recent research indicates your rocky snowball is actually a negative of the actual object - it's more like snow packed into a hole strewn rock.

0
0
Bronze badge
Thumb Up

Thanks!

It's been a while (obviously) since I read up.

0
0
IT Angle

Its broken up due to the gravitational forces of entering the solar system. (The sun mostly). Its more common than you think. A lot of our meteor showers are the legacy of disintegrated comets.

0
0
Silver badge
Gimp

Keep denying the truth, looser! Cain's 6-6-6 is already STARTING!!!

G-d is magnificent, then he give us magnicent signs. The times are near we all know, we can feel them. Aliens will show themselves also: watchers, the fallen angels, the annunaki..ppl will blieve in them and not in G-d our creator and father. Each one of us will be making a choice. Prepare the soul, we r free G-d made us free, is ur personal choice BUT U KNOW THE SIGNALS AND HAVE BEEN WARNED. Also check the alignment in 1994 when the cross form in sky with the 4 animals from the revelations...

0
0

Page:

This topic is closed for new posts.

Forums