Let's Deny Ignorance: The Not So Doom-y Truth About Comet ISON

ThePeaceMaker
...could this theoretically cause the fragments to change course?

Well naturally a bit breaking off will be going on a different course, but the path of it is still constrained by the laws of physics.

Consider this:
Right now, comet ISON is moving at a speed determined by orbital mechanics, and the details of such orbits have been known for hundreds of years. An object in orbit around the sun moves in ways known to Kepler, back in the 1600's.
The orbit of comet ISON is known from thousands of observations, and so we can state with great certainty that it is currently moving at 230,000 miles per hour.

Read that again. 230,000 miles per hour.
At perihelion, at its fastest, it will be moving at 845,000 miles per hour.

So lets assume a bit breaks off, and explodes away from the comet at a massive 1000 miles per hour.

In comparison to the orbital speed it already has, thats only a small fraction of its momentum. Despite earlier claims that "NASA has no way of calculating...", you can even see without such calculations that to all intents and purposes the direction and velocity of the broken off bits is largely the same as the original comet.

Even for a bit to simply come to a stop, it would have to explode away in the reverse direction at 230,000 miles per hour. Isnt going to happen. And you doomsdayers want to send a large chunk flying in the direction of earth? Isnt going to happen.

You can of course do the calculations for yourself.
Exactly how much energy does it take to send a large chunk, lets say 1 mile across, flying away at a significant speed, lets say 1,000,000 miles per hour? (And what magical unicorn is going to provide that energy?)

reply to post by Nodrak


The Oberth Effect is not quite the same as a object breaking up under stresses.

It is even not quite the same if something in the comet exploded, as the Oberth Effect is dealing with thrust over time. Not sudden impulse with a immediate decline in energy (high velocity explosion).

Even if material inside the comet were to in turn rupture and leave the comet at high velocity (IE like a rocket engine), ask yourself this:

"Would said venting material have enough velocity to change the orbit of a 3 to 5km object made of solid material, given that it looks like it's velocity will be 425,000 mph (684,000 kph, or 118 miles per second, or 190 kilometers per second)?"

Remember: the Oberth effect is where the use of a rocket engine when travelling at high speed generates more useful energy than one at low speed.

The only way that this would work, again, is if the comet started venting enough material to impart enough reaction thrust, in the same direction over time (most objects in space that are not human made are tumbling).

Could the venting material cause the comet to spin? Change any spin it has? Slow down or even stop a spin?

Absolutely, as the energy of that spin or tumbling is a lot less than is currently imparted in the actual orbit of the comet.

All this is all conjecture that the comet has something inside of it that will cause it to explode, or vent enough mass at high velocity.

None of the above speculation applies if it simply fragments under gravitational tides from the sun, coupled with the extreme temperatures of being so close to the sun.

reply to post by alfa1
it seems ison has disintegrated,that comet is already one big ball of gravel,how much will that ball of gravel disperse?Any iron in ison?solar wind,magnetism and huge gravitational forces may spread this sucker far and wide.

Legion2024
Would there be enough matter in ISON to change the dynamic of the sun if it was to hit. And if it did would the change in fuel being burnt change the suns colour, and how much effect would that have on earth..?

Uhm, no.

The amount of material making up the sun is so much more massive than the comet, it would be like if you dropped a single grain of salt in a 20,000 gallon pool of fresh water. It would not change the pools salinity at all.

The sun is the color it is because of the temperature of it's surface.

symptomoftheuniverse
how much will that ball of gravel disperse?Any iron in ison?solar wind,magnetism and huge gravitational forces may spread this sucker far and wide.

So you didnt actually bother reading my post, then?

Read that again. 230,000 miles per hour.

So... you've got a bit of gravel moving instead at 230,001 miles per hour instead of 230,000 miles per hour. Exactly how does that spread the bits "far and wide"?
Answer: it doesnt. The orbit of that bit only changes by 0.0000043.
You'd not even notice it if you drew a picture of the orbit on paper.

DJW001

Iamschist
See, I bet if we look back in ATS history this is how it started for Phage, an innocent sincere effort to educate.....lol Well done!

Say, that reminds me: I haven't seen Phage since I got out of sickbay. What's up with that?

What I've found strange is the lack of input resident Phage has on these string of ISON threads. Historically, these threads seem like the type in which Phage would have a field-day with...making quick work of the nonsense. Maybe he has finally had enough, as this topic seems relentless and ignorant despite conclusive and factual rebuttal. It's probably not worth his time anymore unfortunately, as the wave of ISON threads produced by the mentally vulnerable won't flame out until the comet physically expires. However, there are those who are sincerely looking for clarification and willingly accept the debunking of a thread which they authored--others...not so much. I just don't understand how people can post sensational titles based solely on Youtube videos, before asking themselves "Has this been researched and explained already? Should I verify and study this myself before I post this as a plausible topic for discussion?". People need to be more skeptical of their own research and examine it logically instead of mindlessly submitting the first bit of nonsense they come across. If you are unsure, kindly ask the ATS community in the form of a question if your potential contribution is legit..rather than dictating a sensational headline that suggests proof.

alfa1

symptomoftheuniverse
how much will that ball of gravel disperse?Any iron in ison?solar wind,magnetism and huge gravitational forces may spread this sucker far and wide.

So you didnt actually bother reading my post, then?

Read that again. 230,000 miles per hour.

So... you've got a bit of gravel moving instead at 230,001 miles per hour instead of 230,000 miles per hour. Exactly how does that spread the bits "far and wide"?
Answer: it doesnt. The orbit of that bit only changes by 0.0000043.
You'd not even notice it if you drew a picture of the orbit on paper.

edit on pmTuesdayfpm1 by alfa1 because: (no reason given)

i did read your post so may be you can describe how shoemaker/levy mangaged to disintegrate.jeeze

symptomoftheuniverse
i did read your post so may be you can describe how shoemaker/levy mangaged to disintegrate.jeeze

Shoemaker–Levy 9 is an excellent example proving my point.

It broke up during a close pass of Jupiter around the date of July 7, 1992, and met its demise when it crashed into Jupiter on July 16, 1994.

So thats two whole years in which its different fragments were being spread "far and wide" as you put it.

BUT

All the bits crashed into Jupiter.
So no, they did not spread "far and wide" at all.

The different parts were spread out in a "chain". As I said in my opening post, its more like a disconnection of carriages on a train.

Any breakup of comet ISON will always have been much the same. The different bits would always have been ending up travelling in much the same orbital path.
Doomsdayers who think they bits will just go spinning randomly off in random directions to random parts of the solar system are very much mistaken. Proven wrong by calculations. Proven wrong by previous examples.

Edit - we can do calculations.
The chain of bits of comet SL-9 was 162,000 km in length. Thats after 2 years.
Or to put it another way, a differential speed of 6750km per month, or just 9.2km per hour.
Thats just under 6 miles per hour.
Are you scared of bits of a comet breaking off at 6 miles per hour?

Scurrilous
What I've found strange is the lack of input resident Phage has on these string of ISON threads. Historically, these threads seem like the type in which Phage would have a field-day with...making quick work of the nonsense.

The truth of the matter is that Phage is not foolish enough to make reckless assumptions about what has already been labeled by NASA as "the possible comet of the century".

Maybe he has finally had enough, as this topic seems relentless and ignorant despite conclusive and factual rebuttal.

I doubt that at all. I believe that it's more likely that Phage doesn't want to have to remove his foot from his mouth, so he is waiting for some scientific data to back up the theories that up until now, have all been based on former observations. Phage is actually being Phage, he's using his head.

It's probably not worth his time anymore unfortunately, as the wave of ISON threads produced by the mentally vulnerable won't flame out until the comet physically expires.

Actually it is worth his time, because that is what he does. However, he is intelligent enough to understand that this universe is unpredictable, and there is a lot of unknown coming our way, as well as what is just out there. I am sure he will show up soon enough though. Surely if ISON survives the Sun he will. ~$heopleNation

reply to post by Scurrilous


Actually, it was kind of the same with all the Nibiru or PlanetX threads last year. He did post in some, but pretty much dropped out towards the last half of the year.

Guess he simply threw his hands up.

eriktheawful
reply to post by Nodrak

 

The Oberth Effect is not quite the same as a object breaking up under stresses.

It is even not quite the same if something in the comet exploded, as the Oberth Effect is dealing with thrust over time. Not sudden impulse with a immediate decline in energy (high velocity explosion).

Even if material inside the comet were to in turn rupture and leave the comet at high velocity (IE like a rocket engine), ask yourself this:

"Would said venting material have enough velocity to change the orbit of a 3 to 5km object made of solid material, given that it looks like it's velocity will be 425,000 mph (684,000 kph, or 118 miles per second, or 190 kilometers per second)?"

Remember: the Oberth effect is where the use of a rocket engine when travelling at high speed generates more useful energy than one at low speed.

The only way that this would work, again, is if the comet started venting enough material to impart enough reaction thrust, in the same direction over time (most objects in space that are not human made are tumbling).

Could the venting material cause the comet to spin? Change any spin it has? Slow down or even stop a spin?

Absolutely, as the energy of that spin or tumbling is a lot less than is currently imparted in the actual orbit of the comet.

All this is all conjecture that the comet has something inside of it that will cause it to explode, or vent enough mass at high velocity.

None of the above speculation applies if it simply fragments under gravitational tides from the sun, coupled with the extreme temperatures of being so close to the sun.

You are still incorrect. The oberth effect is based on impulse, which is Force * Time, which allows for a small force over a long period to produce the same effect as a large force over a short period of time (ie, explosive outburst or a slow venting). The important part is the Oberth Effect relies on the Kinetic Energy of a moving object to provide additional energy when expelled due to thermodynamics. The comet's mass is this energy, much like a rocket. A rocket wont disintegrate itself for more thrust on purpose, but if it did, it would still benefit from the oberth effect. Once an object reaches a certain velocity (around 3k m/s), the kinetic energy of the fuel is much greater than the chemical reaction energy of the same fuel.

You seem to be stuck on the flawed understanding that large numbers are hard to change, but that is entirely incorrect. I don't have numbers for ISON's mass or such, but lets say that is has X Mass. Therefore it has 1/2*X*V energy. If that mass is made up of some potentially gaseous matter, like ice, or even metallic materials if the temperature gets hot enough. So lets say 1/100th of the mass explodes in a way that much of the force is directed pro-grade (or retrograde), which is entirely possible, even if its not probable.

Since I don't have numbers on hand for the speed of a hot gaseous outburst in a vacuum, lets say its something like Mach 1 or something. So 0.3 KM/s, with ISON moving at roughly 125 KM/s currently.

The energy provided by this would be 1/2 * 1/100 * X * (125.3), either added to or subtracted from ISON's energy depending on direction. The energy imparted to ISON would be 0.6265 * X, while ISON would have, 61.875 * X energy. The gas venting would change ISON's energy by 1.013%, or 1.006% of its velocity.

So, if 1% of the mass of ISON vented out at the speed of sound, the velocity change would be on the order of 1.25 KM/s. This is enough delta-v to take anything from a Lunar Orbit to a Low Earth Orbit. I don't have the numbers to bother calculating the effect on the orbit of ISON in terms of distance in KM, but if the gas vents faster than 300 m/s, or more mass vents, the delta-v rises extremely quickly.

Now as the predicted path of ISON is not inline with the earth's orbital plane, it would be extremely unlikely that any forces happening on the sundive would push its orbit closer to earth, due to Orbital Plane Change issues at low orbits.

That being said, I hope you see where you are wrong in assuming that because the numbers are large nothing can significantly influence them. Your other points about rotation and such are valid, but not your assumptions on orbital velocities and maneuvers...

On the topic of Shoemaker-Levy 9. That comet broke up due to tidal forces. Such a comet would ultimately also be broken up by solar tidal forces, but one has to consider that such a weakly formed comet would also experience forces from the solar wind and thermal shock, leading it behave much differently than observed around the ice cold temperatures of a Jupiter orbit.

alfa1

symptomoftheuniverse
i did read your post so may be you can describe how shoemaker/levy mangaged to disintegrate.jeeze

Shoemaker–Levy 9 is an excellent example proving my point.

It broke up during a close pass of Jupiter around the date of July 7, 1992, and met its demise when it crashed into Jupiter on July 16, 1994.

So thats two whole years in which its different fragments were being spread "far and wide" as you put it.

BUT

All the bits crashed into Jupiter.
So no, they did not spread "far and wide" at all.

The different parts were spread out in a "chain". As I said in my opening post, its more like a disconnection of carriages on a train.

Any breakup of comet ISON will always have been much the same. The different bits would always have been ending up travelling in much the same orbital path.
Doomsdayers who think they bits will just go spinning randomly off in random directions to random parts of the solar system are very much mistaken. Proven wrong by calculations. Proven wrong by previous examples.

Edit - we can do calculations.
The chain of bits of comet SL-9 was 162,000 km in length. Thats after 2 years.
Or to put it another way, a differential speed of 6750km per month, or just 9.2km per hour.
Thats just under 6 miles per hour.
Are you scared of bits of a comet breaking off at 6 miles per hour?

edit on pmTuesdayfpm1 by alfa1 because: (no reason given)

comets break appart simple as that. Shot gun pellets spread out after leaving the barrel. If its gravel is hold together with ice then the heat of the sun has already started dispersing the lumps.Ice exploding at 5000c is a bit more than 6mph. The sun and jupiter are very different vegetables. Oh and they deduced that levy must have broke up on a previous orbit. So gravity alone broke up shoemaker levy 9.

symptomoftheuniverse
So gravity alone broke up shoemaker levy 9.

Yes it did, but nobody is saying comets dont break up. There have been many previous examples.

symptomoftheuniverse
Ice exploding at 5000c is a bit more than 6mph.

A "bit more"?
Pick a number then, based on plausible physics.
We'll do some calculations.

alfa1

symptomoftheuniverse
So gravity alone broke up shoemaker levy 9.

Yes it did, but nobody is saying comets dont break up. There have been many previous examples.

symptomoftheuniverse
Ice exploding at 5000c is a bit more than 6mph.

A "bit more"?
Pick a number then, based on plausible physics.
We'll do some calculations.

ok the comet begins to disintegrate say half way between earth and venus. The ice sends fragments in all directions. The ice is consumed inside the orbit of mecury. How wide will the debris cloud be when the remnants reach closest approach to earth.

reply to post by SheopleNation


I'm quite aware of the intelligence and input Phage projects, and the fact that he carefully articulates his contributions based on fact. However, I noticed his frustration last year on many threads concerning Nibiru and Elenin, which he eventually seemed to give up on. I don't think it's a matter of him being afraid to get caught with his foot in his mouth, as he always offers intelligent insight relative to the data and information he has available. Phage doesn't tend to make claims that can't be backed up; given the wealth of information we have at this time regarding ISON, I don't see why he would refrain. I think he sincerely has a lack of interest in expending and wasting his time trying to educate those who are unwilling to listen as he has in the past. I think he should put his knowledge to work on the more complex and confusing topics, as this "ISON" debate is obviously not (other than to those stubborn enough to ignore fact). On the bright side, we have members such as the author of this thread who are quite capable of cleaning up the garbage effectively.

Thank you Dary for saying what I am sure many of us feel!!

I have seen many youtubers that just ram it into the ground that this will destroy Earth, and I think I know exactly the folks your are talking about...it really does get annoying, although I will admit a few are entertaining in an odd way LOL!

If it truly was going to destroy earth, our collective whole as humans would seriously be in a panic. I don't think it would be able to be kept quiet! Also, if it were real and the powers that be really wanted it to be a secret, I think we would hear about more accidental deaths if ya know what I mean.

As for asteroids, well that is a different story all together in my opinion. I think we actually need more backyard astronomers to keep an eye out, there are many of them out there. Just look at what happened in Russia earlier this year for example.


Here is a fun site, as it lets you see the size and approach dates. Although they are not ELE they can still cause considerable damage. Just look at the upcoming approaches to Earth. It's like a battlefield out in space.

neo.jpl.nasa.gov

symptomoftheuniverse
How wide will the debris cloud be when the remnants reach closest approach to earth.

Pick a number then, based on plausible physics.
We'll do some calculations.

alfa1

symptomoftheuniverse
How wide will the debris cloud be when the remnants reach closest approach to earth.

Pick a number then, based on plausible physics.
We'll do some calculations.

how fast would a grenade explode in the vacume in space?

symptomoftheuniverse
how fast would a grenade explode in the vacume in space?

...based on plausible physics.

reply to post by alfa1


And who decides what "plausible physics" is.

And for that matter, who cares.

I believe Phage has realized that suddenly more cool things than quoting textbooks are arriving, and he is now in the process of reviewing MUCH.

It often happens to people when someone is finally able to make them see beyond the "accepted norms".