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

DenyObfuscation
reply to post by Signals

 

But most importantly, NASA has admitted there is no simulation available to predict the pieces' trajectory or speed.

Do you have a source for that? I'd like to check it out.

Right, that doesn't seem accurate, everything I've read says once it's on a course it stays on the course, no matter if it stays together or breaks up into a thousand points of light (gag, couldn't resist that last one, Peggy Noonan has a way with words and George HW had a way to almost say them like he meant them).

reply to post by daryllyn


Excellent thread; presented objectively and rationally with logic at the forefront. I have to say, though I enjoy and entertain a good doom-y notion from time to time, it is quite obvious ISON doesn't qualify. I feel that here on ATS, all perceptions are welcome...as long as they constitute and adhere to a factual mission based on truth. This melting pot of information and ideas make this site one of the most transparent mediums of study available; however, it seems the collective eccentricity of some members often breeds and fuels the influx of misinformation. As I've stated, all ideas here are welcome, but some people really need to put those possibilities in context based on the tangible body of evidence available. Obviously, the less proof... the less probable--no need to cry wolf in all CAPS where it isn't warranted. I'm just glad that some of our most knowledgeable members pride themselves on taking an initiative to dissolve futile ignorance and ultimately educate the culprits (though they rarely admit it). If you really seek that doom-y thrill, at least show a willingness to find some actual "doom"...as I'm sure the only doom we have to worry about at the moment is right here on earth as opposed to a sudden galactic catastrophe only noticed by a few guys with Youtube accounts. Come one people, conspiracy site or not, we're all supposed to be "above" this. Again, great job daryllyn. S and F!

You're my new favourite person and you win all the internets today.

I've been keeping up with these ISON doom porn threads for a while now and, at times, I've wanted to hurl my iPad into a wall out of sheer frustration. The ignorance and blind conviction of some people on here is staggering.

Anyway, well said. Though I doubt it will change anything, it needed to be said and I'll continue to support common sense where I can. Why people enjoy living in constant fear is beyond me......

reply to post by Signals


Newton's Laws of Momentum, Laws of Motion and Orbital Mechanics basically says:

Nope.

In order to change the orbital path of an object, especially one as massive as a comet 3 to 5 km across, one would need to impart enough energy to it to cause that change.

The sun's gravity is doing that, and controls the direction that the comet is heading.

If the comet breaks up, the momentum that it already has, coupled with the laws of motion, show that a break up of any kind is simply not enough energy to impart a major change it the orbit of the debris.

Grab a bunch of marbles. Hold them tightly in your hand, and throw them all in one direction. Even though the marbles part ways (like let us say, a break up of a comet) all the marbles keep going in the same direction as they were thrown.

Now think of a clay pigeon target. A person shots a shotgun at it. It shatters and the pieces of it DO scatter and go into all sorts of directions. Why?

Because the shotgun pellets hitting the clay pigeon impart much more energy to the clay pigeon than the catapult that threw it.

So the only way you are going to get any fragments of ISON (if it breaks up) to change direction, is by over coming the sun's energy that it has imparted into the mass of the comet with it's gravity.

That means, you'll need to go out there, and strap one heck of a rocket motor on it (bigger than anything we have right now), and light it off.

daryllyn
So, there you have it, folks. ISON is just a comet, it poses no danger to earth,

What?? No doom? That's depressing..
Thanks for the heads up tho..I guess I'll show up for work tomorrow..

Let's get this right. You mean this comet is not Planet X, an alien spaceship, or a bringer of the black death? Having spent many hours debating whether I should stock up on cans of beans or blow all my remaining funds on having a final blast, I'm a little disappointed. It means I will have to confront reality - which is how to afford the car repairs, the broken shower, the drainage problem round the back, heating for the UK winter.......
Comet Ison was my get-out clause....

reply to post by Aleister


There may be explosions within the nucleus itself, as it superheats and breaks apart.

In an explosion, pieces fly out in all directions...

We do not possess the computing power to simulate how many pcs, how big are they, and what direction they will go.

It is not possible to simulate. All computer trajectory models are assuming it remains intact.

Flaunt

I've been keeping up with these ISON doom porn threads for a while now and, at times, I've wanted to hurl my iPad into a wall out of sheer frustration. The ignorance and blind conviction of some people on here is staggering.

Why bother clicking the doom porn threads if it bothers you that much?

reply to post by Signals


I'm sorry, but that's not quite true.

We might not be able to predict exactly how many pieces might form, but we can certainly can tell if they will change orbit or not:

Ke=(mv^2)/2

By knowing the comet's mass, and it's velocity, we know how much energy it has.

In order for ANY piece of the comet, no mater it's size in mass, to change orbits, it MUST OVERCOME that energy already there.

And considering the velocity it has right now, the theoretic explosion would need to be on the order of many hundreds of megatons.

Any one (even with out a computer) can sit down and compute how much energy would be released if the entire comet was made up of something that could explode, and figure out how much energy that would impart.

Using the above formula, anyone, with nothing more than pencil and paper, and figure out the amount of energy the comet already has.

And unless your theoretic explosion can exceed the comet's mass times it's velocity (huge right now) squared, divided by 2, the pieces are not going to go anywhere too far from the orbital path it is on.

reply to post by Tucket


Probably because they don't state "Doom Porn" in the title? Also, they relate to ISON and if you haven't noticed there is plenty of discussion regarding this comet. Therefore, everyone is eager to separate fact from fiction and dispose of the fabrications. Isn't that what this site is about? Also, studying and being able to identify the misinformation only strengthens and distinguishes your understanding of the truth (hence you can quickly identify fallacies and eliminate them when used on the other side of a debate).

Damn all these scientific facts, getting in the way of a good scare story.

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?

reply to post by eriktheawful


Agreed, but you fail to mention there are always exceptions. In your example if one or more marbles, or piece of comet, impacts another during breakup or contact with x flare it could send the object off trajectory.

Look my problem is nasa is my money, they have the best toys. You can look at the video and still shots yourself. You can see enke, three kilometers in size and ison. All accounts, even nasa says ison is twenty million, million with a big M further away than enke. Ison dwarfs enke.

I just don't see what the big deal is. One thing is for sure folks, we are gonna get great shots as it either hits the sun or makes it around as SDO is going to tilt the cameras to give shots as it comes around. Should be great.

I also find it perplexing why nasa waited until ison as hit with second x flare before talking about it. They said nothing as the first one stripped the tail. Ison is rebuilding electrical potential but it was hit with another flare.

I think it is going to be fun the next few days. I think it is going to dive into the sun myself but hey that brings up even more doom porn scenarios lol.

For me guys nasa has been all over the map on this one and it's my money. I would rather spread their toys out to scientists all over the world. Despite daryllyn excellent post I question how nasa spends/wastes our money sometimes.

Happy thanksgiving and ison watching lol, hope all has a great holiday, be safe, god bless

The Bot

reply to post by alfa1


But..wouldn`t the suns gravitational pull have a greater effect on the smaller pieces than on the larger pieces?
wouldn`t the smaller pieces be diverted more from their original course than the larger pieces?

Scurrilous
reply to post by Tucket

 

Probably because they don't state "Doom Porn" in the title? Also, they relate to ISON and if you haven't noticed there is plenty of discussion regarding this comet. Therefore, everyone is eager to separate fact from fiction and dispose of the fabrications. Isn't that what this site is about? Also, studying and being able to identify the misinformation only strengthens and distinguishes your understanding of the truth (hence you can quickly identify fallacies and eliminate them when used on the other side of a debate).

Doom porn isn't stated in the titles, but often it's suggested.
And why would a doom porn thread make someone wanna throw their iPad against the wall out of frustration?
Really, who cares?
Take it for what it is, cheap entertainment.

reply to post by eriktheawful


Theres always the WHAT IF. .0000008% is still a possibility.

What if the nucleus contained fuel trapped in it much like we use to boost rockets into space.

A hole forms on the outer membrane which releases the propellant then its ignited by the sun and now we have a comet with a rocket engine. Yes im thinking outside the box.

I think what many are trying to get at is there is always the possibility of something not going to plan and some strange new thing could happen. We just don't know. Even with computer models and technology you wont know until it happens.

eriktheawful
reply to post by Signals

 

I'm sorry, but that's not quite true.

We might not be able to predict exactly how many pieces might form, but we can certainly can tell if they will change orbit or not:

Ke=(mv^2)/2

By knowing the comet's mass, and it's velocity, we know how much energy it has.

In order for ANY piece of the comet, no mater it's size in mass, to change orbits, it MUST OVERCOME that energy already there.

And considering the velocity it has right now, the theoretic explosion would need to be on the order of many hundreds of megatons.

Any one (even with out a computer) can sit down and compute how much energy would be released if the entire comet was made up of something that could explode, and figure out how much energy that would impart.

Using the above formula, anyone, with nothing more than pencil and paper, and figure out the amount of energy the comet already has.

And unless your theoretic explosion can exceed the comet's mass times it's velocity (huge right now) squared, divided by 2, the pieces are not going to go anywhere too far from the orbital path it is on.

edit on 26-11-2013 by eriktheawful because: (no reason given)

I had to sign up just to tell you that you are incorrect. You need to research orbital mechanics if you are going to pretend to talk about them like you have all the facts. A good starting point would be to look up the OBERTH EFFECT. While this tends to apply to vehicles with rocket fuel propellant, one can consider the comet itself as a potential fuel source, since the oberth effect is primarily based on the speed of a propellant moving in the opposite direction of desired thrust. It is possible that the comet could heat up and release gases that have immense stored kinetic energy as you mention, which would provide possibly dramatic levels of delta-v.

The other thing to consider about orbital maneuvers is that when you are in a close orbit to a body, small changes in velocity along the pro-grade vector will have a massive effect on the location of the apoapsis. Most people understand this as the slingshot effect, but that is a simple example focused on increasing speed rather than making course adjustments with minimal fuel use.

One area you are correct in is that it would take immense energy to alter the orbital plane of the commit when it is close to the sun. So, in short, if ISON's orbital plane intersects earth's, there is still much potential for collision. If the planes do not intersect, it is extremely unlikely the comet plane will change as the impulse would have to be massive.

Cheers.

Just a quick one this is a question I have no expertise in the ISON/comets subject. But say ISON starts to fragment if a pocket of some sort of gas inside that had been built up over time was to explode from the inside out could this theoretically cause the fragments to change course?

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..?

daryllyn
Thanks for clarifying that.

Once again, the truth proves to be far less doom-y than its fictitious counterpart.

Only that is far from the truth. It may have been the truth thus far, but they are scientific theories and assumptions which are all based on former observations of earlier comets. We still don't completely understand the effects that our Sun has on the orbital paths of every single comet or asteroid. The unknown must be taken into consideration, because science is about checks and balances.

I will say it again, all Comets and Asteroids do not behave the same. That IS why numerous Scientists and astronomers worldwide have repeatedly made the statement that this is unlike any Comet before. That is also why NASA themselves have also called c/2012 S1 ISON "a potential comet of the century". Is there doom and gloom out there? Absolutely you're correct about that.

Now I personally believe that it will survive the Sun, and then continue it's journey to whatever other system's direction it is heading, but anything is possible in this crazy Universe.

I expect us to see some nice meteors and a few possible small meteorites impact during the time that planet Earth passes through ISON's tail. ~$heopleNation