Godlike Productions - Discussion Forum
Users Online Now: 1,576 (Who's On?)Visitors Today: 315,444
Pageviews Today: 515,036Threads Today: 172Posts Today: 2,995
07:18 AM


Rate this Thread

Absolute BS Crap Reasonable Nice Amazing
 

Can ISON hit the Earth? WARNING math inside

 
Anonymous Coward
User ID: 24685096
Philippines
12/01/2013 11:32 PM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Here's why a sizable chunk of ISON can actually hit earth.

1, After perihelion, ISON broke into several pieces, and it is unknown how large these pieces are. So ISON's tail cannot be assumed to be made of small micron sized dust particles anymore.

2. After perihelion, ISON's tail is no longer pointing away from the Sun, in fact, a portion of its widely spread out tail is angled pointing downwards (with respect to the ecliptic plane). This means when it passes almost directly on top of the earth (with respect to the ecliptic plane), it is possible that a chunk trailing the comet could actually hit earth.
Thread: isons tail is the wrong way!!!
Theguywhofearsnomore
User ID: 50810475
United States
12/01/2013 11:33 PM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Literally anything is possible, space has far too many variables to accurately state what anything is going to do exactly, at least with our current knowledge.

Rough estimates is all science has ever been, they just get more well defined, but can never be perfect unless every possible variable is taken into account.
Anonymous Coward
User ID: 50432294
Canada
12/01/2013 11:40 PM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
YES IT CAN!!

Listen to scientist from MIT explain how Ison threatens the Earth:


 Quoting: Anonymous Coward 50432294



That can't be a scientist from MIT.

I've picked up more than one item that would never have been mentioned by such an individual, and I quit a few minutes into the video.

Besides, what valid scientist uses a fake voice to make a scientific presentation.

This was done by a 5th grader...
 Quoting: Anonymous Coward 22849365


That's the esteemed Dr. Raymond Brown, one of the world's top astrophysicists. He's worked on NASA Apollo and Raytheon - easily the best mind on comets in our solar system!
Anonymous Coward
User ID: 9188459
Canada
12/01/2013 11:44 PM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
I am not an astronomer but have basic knowledge of Newton physics. My goal here is to estimate how much energy we need in order to change the course of Ison so it will hit the Earth.

So let's start.

t: it takes 28 days for ISON to reach the Earth from Sun (2.4 x 10e6 sec)

Se: closest approach to the Earth 63,000,000 km (6.3 x 10e10 m)

Ss: distance from Earth to Sun: 149,600,000 km (1.5 x 10e11 m)

Vi: speed of Ison 86000 m/s = 8.6 x 10e4 m/s

m: estimated mass 7,000,000,000 kg (7 x 10e12 g) to 7,000,000,000,000 kg (7 x 10e16 g) from [link to www.nasa.gov] , for our calculation we take lower number.

angle between Earth - Sun - Projected Ison path
atan(Se/Ss) = atan(6.3 x 10e10 / 1.5 x 10e11) = atan(0.2625) = 14.7 degrees

This is how much the course of Ison or one of its debrees must be changed in order to hit the Earth.

The speed we need to push Ison in perpendicular vector towards the Earth
V = Se/T = 6.3 x 10e10 / 2.4 x 10e11 = 2.6 x 10e4 = 26000 m/s

This is how much energy needed to do that:
E = mVxV/2 = 7 x 10e12 x 6.76 x 10e8 / 2 = 2.4 x 10e21 Joels

(1 kiloton of TNT equals to 5 x 10e12 Joels so we need
2.4 x 10e21 / 5 x 10e12 of kilotons = 4.8 x 10e8 kilotons = 30,000,000 Hiroshima bombs)

It looks a lot but considering total Kinetic energy of Ison:

8.6x8.6x 10e8 x 7 x 10e12 / 2 = 259 x 10e20 = 2.6 x 10e22 Joels = 5.2 x 10e9 kilotons = 325,000,000 Hiroshima bombs

we need only 9% of the total Ison energy to be redirected in order to change the course towards the Earth.
It does not look a lot.

Let's take only small chunk of Ison (we don't need the full comet for the disaster. For example for one Million of Hiroshima bomb we need 1/325 of Ison's mass thus it is enough to redirect 9%/325 = 0.028% of the total Ison energy to change the course of this chunk.
Remember we used lowest mass estimation. So the number can be even less.

Astromut and other experts!
Am I wrong? If yes show where.
 Quoting: Sergman



try this


[link to en.wikipedia.org]



.
Anonymous Coward
User ID: 48442153
Canada
12/02/2013 01:03 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Do you think Venus can perturb the debris trail somehow?
Anonymous Coward
User ID: 48442153
Canada
12/02/2013 01:15 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Do you think Venus can perturb the debris trail somehow?
 Quoting: Anonymous Coward 48442153


Nvm I just realized how far away ISON will be from Venus.
SOON
User ID: 50787870
United States
12/02/2013 01:21 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
the moon u all thought I was nuts about it speeding up well dang it did
Anonymous Coward
User ID: 50779528
Greece
12/02/2013 02:55 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Sorry, but your Physics are of high school level and do not consider other masses than the mass of Earth and ISON, nor you have used vectors to understand that ISON is not heading to Earth at all. The trajectories are not linear and are 3D, not 2D. You have a long way of learning until you master Celestial Mechanics. In the end, you'll learn that you need a computer to actually simulate a celestial system, since it is chaotic due to the involvement of more than two bodies (the three body and the n-body problems in Celestial Mechanics are famous). For the moment you should know that orbits are close to conical sections (circle,ellipse,parabola,hyperbola), though they are altering constantly due to the exact chaotic nature of celestial mechanics. There is no fear with ISON hitting Earth.
Anonymous Coward
User ID: 50920395
Germany
12/02/2013 03:01 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Thanks OP, sounds legit
Anonymous Coward
User ID: 11995984
United States
12/02/2013 03:15 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
some force would have to affect it by the 17th or before in order to change it's path to come anywhere near Earth by Christmas or the end of the year...otherwise you'll need a direct 'cue ball' hit to send it 90 degrees South to hit us during that time frame at the end of the month.
Anonymous Coward
User ID: 50779528
Greece
12/02/2013 03:27 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Sorry, but your Physics are of high school level and do not consider other masses than the mass of Earth and ISON, nor you have used vectors to understand that ISON is not heading to Earth at all. The trajectories are not linear and are 3D, not 2D. You have a long way of learning until you master Celestial Mechanics. In the end, you'll learn that you need a computer to actually simulate a celestial system, since it is chaotic due to the involvement of more than two bodies (the three body and the n-body problems in Celestial Mechanics are famous). For the moment you should know that orbits are close to conical sections (circle,ellipse,parabola,hyperbola), though they are altering constantly due to the exact chaotic nature of celestial mechanics. There is no fear with ISON hitting Earth.
 Quoting: Anonymous Coward 50779528


we want new trajectory calculations with new data points
based on ISONs present path and projected out to wherever it
gets closest to Earth.
(and we don't require info on the rest of the Orbit)

get'er done.
 Quoting: Littlefeather


You should know that these quantities change and having just the current position and velocity, won't actually tell you much about when and where is the closest approach of the two celestial bodies. We are not talking about linear trajectories here but for conical section ones with constantly changing coefficients. ISON and Earth are not the only two objects in this solar system and even between them there is an angular momentum that would prevent linear motion even if they were the only ones.
Sergman  (OP)

User ID: 43941380
Canada
12/02/2013 03:28 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Sorry, but your Physics are of high school level and do not consider other masses than the mass of Earth and ISON, nor you have used vectors to understand that ISON is not heading to Earth at all. The trajectories are not linear and are 3D, not 2D. You have a long way of learning until you master Celestial Mechanics. In the end, you'll learn that you need a computer to actually simulate a celestial system, since it is chaotic due to the involvement of more than two bodies (the three body and the n-body problems in Celestial Mechanics are famous). For the moment you should know that orbits are close to conical sections (circle,ellipse,parabola,hyperbola), though they are altering constantly due to the exact chaotic nature of celestial mechanics. There is no fear with ISON hitting Earth.
 Quoting: Anonymous Coward 50779528


I am not trying to calculate accurate trajectory. Indeed you need knowledge and supercomputers to do that. But think of this analogy. Before the explosion Ison was like a sniper bullet. You know exactly where it will hit. But after the event it is more like a shotgun. You don't need to aim! The fragmentation of the comet has less or more conical shape. You don't calculate new pass for each and every segment. It is virtually impossible. They don't even know the size of this monster. So what we have here is equation with infinite parameters. We just can estimate what will happen. In my calculation I just show that you need a small portion of the energy to change the course.

Last Edited by Sergman on 12/02/2013 03:29 AM
:bdance:
Anonymous Coward
User ID: 50779528
Greece
12/02/2013 03:41 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Sorry, but your Physics are of high school level and do not consider other masses than the mass of Earth and ISON, nor you have used vectors to understand that ISON is not heading to Earth at all. The trajectories are not linear and are 3D, not 2D. You have a long way of learning until you master Celestial Mechanics. In the end, you'll learn that you need a computer to actually simulate a celestial system, since it is chaotic due to the involvement of more than two bodies (the three body and the n-body problems in Celestial Mechanics are famous). For the moment you should know that orbits are close to conical sections (circle,ellipse,parabola,hyperbola), though they are altering constantly due to the exact chaotic nature of celestial mechanics. There is no fear with ISON hitting Earth.
 Quoting: Anonymous Coward 50779528


I am not trying to calculate accurate trajectory. Indeed you need knowledge and supercomputers to do that. But think of this analogy. Before the explosion Ison was like a sniper bullet. You know exactly where it will hit. But after the event it is more like a shotgun. You don't need to aim! The fragmentation of the comet has less or more conical shape. You don't calculate new pass for each and every segment. It is virtually impossible. They don't even know the size of this monster. So what we have here is equation with infinite parameters. We just can estimate what will happen. In my calculation I just show that you need a small portion of the energy to change the course.
 Quoting: Sergman


I wouldn't take analogies from every day life experience, nor you need anymore a supercomputer to calculate trajectories (you laptop or even your smartphone can do this very easily now as long as there are as much as possible of celestial objects data in order to achieve the best estimate for orbit perturbations). Someone would need to worry about big fragments of what is left, although they are probably coupled together (there are examples of former comets that were fragmented like that and fragments stayed close together) but there is a small chance that they'll be on a path that crosses the orbit path of the Earth, not to mention of being exactly at the same location at the same time.
Anonymous Coward
User ID: 50779528
Greece
12/02/2013 03:53 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Sorry, but your Physics are of high school level and do not consider other masses than the mass of Earth and ISON, nor you have used vectors to understand that ISON is not heading to Earth at all. The trajectories are not linear and are 3D, not 2D. You have a long way of learning until you master Celestial Mechanics. In the end, you'll learn that you need a computer to actually simulate a celestial system, since it is chaotic due to the involvement of more than two bodies (the three body and the n-body problems in Celestial Mechanics are famous). For the moment you should know that orbits are close to conical sections (circle,ellipse,parabola,hyperbola), though they are altering constantly due to the exact chaotic nature of celestial mechanics. There is no fear with ISON hitting Earth.
 Quoting: Anonymous Coward 50779528


we want new trajectory calculations with new data points
based on ISONs present path and projected out to wherever it
gets closest to Earth.
(and we don't require info on the rest of the Orbit)

get'er done.
 Quoting: Littlefeather


You should know that these quantities change and having just the current position and velocity, won't actually tell you much about when and where is the closest approach of the two celestial bodies. We are not talking about linear trajectories here but for conical section ones with constantly changing coefficients. ISON and Earth are not the only two objects in this solar system and even between them there is an angular momentum that would prevent linear motion even if they were the only ones.
 Quoting: Anonymous Coward 50779528

if you get enough data points of the objects previous travel
along the path then you can interpolate and project
the forward path out to a pretty long way. just tell the little pea brains at NASA to do it.

are you a moron or are you getting paid to obfuscate the truth?

.
 Quoting: Littlefeather


You seem like a person that hasn't done any maths above High School. These trajectories ARE NOT LINEAR and they are closer to CONICAL SECTIONS (CIRCLE,ELLIPSE,PARABOLA,HYPERBOLA) but not exact ones because of the perturbations cause by other masses (you can think of them as conical sections that alter their natural characteristics)! As for measurements, they are done all the time because of the perturbations and because comets tend to lose mass. When NASA was changing the celestial coefficients for ISON (for example from having a hyperbola orbit to an ellipse) it's because ISON was (and continues) losing mass and it got finally trapped by the Sun in an elliptical orbit around him. Even the trajectory of Earth is changing constantly and currently becomes more of a circular, I think.
Anonymous Coward
User ID: 17415392
Australia
12/02/2013 08:46 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
I am not an astronomer but have basic knowledge of Newton physics. My goal here is to estimate how much energy we need in order to change the course of Ison so it will hit the Earth.

So let's start.

t: it takes 28 days for ISON to reach the Earth from Sun (2.4 x 10e6 sec)

Se: closest approach to the Earth 63,000,000 km (6.3 x 10e10 m)

Ss: distance from Earth to Sun: 149,600,000 km (1.5 x 10e11 m)

Vi: speed of Ison 86000 m/s = 8.6 x 10e4 m/s

m: estimated mass 7,000,000,000 kg (7 x 10e12 g) to 7,000,000,000,000 kg (7 x 10e16 g) from [link to www.nasa.gov] , for our calculation we take lower number.

angle between Earth - Sun - Projected Ison path
atan(Se/Ss) = atan(6.3 x 10e10 / 1.5 x 10e11) = atan(0.2625) = 14.7 degrees

This is how much the course of Ison or one of its debrees must be changed in order to hit the Earth.

The speed we need to push Ison in perpendicular vector towards the Earth
V = Se/T = 6.3 x 10e10 / 2.4 x 10e11 = 2.6 x 10e4 = 26000 m/s

This is how much energy needed to do that:
E = mVxV/2 = 7 x 10e12 x 6.76 x 10e8 / 2 = 2.4 x 10e21 Joels

(1 kiloton of TNT equals to 5 x 10e12 Joels so we need
2.4 x 10e21 / 5 x 10e12 of kilotons = 4.8 x 10e8 kilotons = 30,000,000 Hiroshima bombs)

It looks a lot but considering total Kinetic energy of Ison:

8.6x8.6x 10e8 x 7 x 10e12 / 2 = 259 x 10e20 = 2.6 x 10e22 Joels = 5.2 x 10e9 kilotons = 325,000,000 Hiroshima bombs

we need only 9% of the total Ison energy to be redirected in order to change the course towards the Earth.
It does not look a lot.

Let's take only small chunk of Ison (we don't need the full comet for the disaster. For example for one Million of Hiroshima bomb we need 1/325 of Ison's mass thus it is enough to redirect 9%/325 = 0.028% of the total Ison energy to change the course of this chunk.
Remember we used lowest mass estimation. So the number can be even less.

Astromut and other experts!
Am I wrong? If yes show where.
 Quoting: Sergman


Op I checked the math and it looks all good to me.

It still won't hit earth though, because there is nothing that could redirect 9% of ison's energy.

What are you thinking?
 Quoting: Anonymous Coward 50892049


I am not an astronomer but have basic knowledge of Newton physics. My goal here is to estimate how much energy we need in order to change the course of Ison so it will hit the Earth.

So let's start.

t: it takes 28 days for ISON to reach the Earth from Sun (2.4 x 10e6 sec)

Se: closest approach to the Earth 63,000,000 km (6.3 x 10e10 m)

Ss: distance from Earth to Sun: 149,600,000 km (1.5 x 10e11 m)

Vi: speed of Ison 86000 m/s = 8.6 x 10e4 m/s

m: estimated mass 7,000,000,000 kg (7 x 10e12 g) to 7,000,000,000,000 kg (7 x 10e16 g) from [link to www.nasa.gov] , for our calculation we take lower number.

angle between Earth - Sun - Projected Ison path
atan(Se/Ss) = atan(6.3 x 10e10 / 1.5 x 10e11) = atan(0.2625) = 14.7 degrees

This is how much the course of Ison or one of its debrees must be changed in order to hit the Earth.

The speed we need to push Ison in perpendicular vector towards the Earth
V = Se/T = 6.3 x 10e10 / 2.4 x 10e11 = 2.6 x 10e4 = 26000 m/s

This is how much energy needed to do that:
E = mVxV/2 = 7 x 10e12 x 6.76 x 10e8 / 2 = 2.4 x 10e21 Joels

(1 kiloton of TNT equals to 5 x 10e12 Joels so we need
2.4 x 10e21 / 5 x 10e12 of kilotons = 4.8 x 10e8 kilotons = 30,000,000 Hiroshima bombs)

It looks a lot but considering total Kinetic energy of Ison:

8.6x8.6x 10e8 x 7 x 10e12 / 2 = 259 x 10e20 = 2.6 x 10e22 Joels = 5.2 x 10e9 kilotons = 325,000,000 Hiroshima bombs

we need only 9% of the total Ison energy to be redirected in order to change the course towards the Earth.
It does not look a lot.

Let's take only small chunk of Ison (we don't need the full comet for the disaster. For example for one Million of Hiroshima bomb we need 1/325 of Ison's mass thus it is enough to redirect 9%/325 = 0.028% of the total Ison energy to change the course of this chunk.
Remember we used lowest mass estimation. So the number can be even less.

Astromut and other experts!
Am I wrong? If yes show where.
 Quoting: Sergman


Op I checked the math and it looks all good to me.

It still won't hit earth though, because there is nothing that could redirect 9% of ison's energy.

What are you thinking?
 Quoting: Anonymous Coward 50892049
Anonymous Coward
User ID: 17415392
Australia
12/02/2013 09:32 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
I am not an astronomer but have basic knowledge of Newton physics. My goal here is to estimate how much energy we need in order to change the course of Ison so it will hit the Earth.

So let's start.

t: it takes 28 days for ISON to reach the Earth from Sun (2.4 x 10e6 sec)

Se: closest approach to the Earth 63,000,000 km (6.3 x 10e10 m)

Ss: distance from Earth to Sun: 149,600,000 km (1.5 x 10e11 m)

Vi: speed of Ison 86000 m/s = 8.6 x 10e4 m/s

m: estimated mass 7,000,000,000 kg (7 x 10e12 g) to 7,000,000,000,000 kg (7 x 10e16 g) from [link to www.nasa.gov] , for our calculation we take lower number.

angle between Earth - Sun - Projected Ison path
atan(Se/Ss) = atan(6.3 x 10e10 / 1.5 x 10e11) = atan(0.2625) = 14.7 degrees

This is how much the course of Ison or one of its debrees must be changed in order to hit the Earth.

The speed we need to push Ison in perpendicular vector towards the Earth
V = Se/T = 6.3 x 10e10 / 2.4 x 10e11 = 2.6 x 10e4 = 26000 m/s

This is how much energy needed to do that:
E = mVxV/2 = 7 x 10e12 x 6.76 x 10e8 / 2 = 2.4 x 10e21 Joels

(1 kiloton of TNT equals to 5 x 10e12 Joels so we need
2.4 x 10e21 / 5 x 10e12 of kilotons = 4.8 x 10e8 kilotons = 30,000,000 Hiroshima bombs)

It looks a lot but considering total Kinetic energy of Ison:

8.6x8.6x 10e8 x 7 x 10e12 / 2 = 259 x 10e20 = 2.6 x 10e22 Joels = 5.2 x 10e9 kilotons = 325,000,000 Hiroshima bombs

we need only 9% of the total Ison energy to be redirected in order to change the course towards the Earth.
It does not look a lot.

Let's take only small chunk of Ison (we don't need the full comet for the disaster. For example for one Million of Hiroshima bomb we need 1/325 of Ison's mass thus it is enough to redirect 9%/325 = 0.028% of the total Ison energy to change the course of this chunk.
Remember we used lowest mass estimation. So the number can be even less.

Astromut and other experts!
Am I wrong? If yes show where.
 Quoting: Sergman


Op I checked the math and it looks all good to me.

It still won't hit earth though, because there is nothing that could redirect 9% of ison's energy.

What are you thinking?
 Quoting: Anonymous Coward 50892049


I am not an astronomer but have basic knowledge of Newton physics. My goal here is to estimate how much energy we need in order to change the course of Ison so it will hit the Earth.

So let's start.

t: it takes 28 days for ISON to reach the Earth from Sun (2.4 x 10e6 sec)

Se: closest approach to the Earth 63,000,000 km (6.3 x 10e10 m)

Ss: distance from Earth to Sun: 149,600,000 km (1.5 x 10e11 m)

Vi: speed of Ison 86000 m/s = 8.6 x 10e4 m/s

m: estimated mass 7,000,000,000 kg (7 x 10e12 g) to 7,000,000,000,000 kg (7 x 10e16 g) from [link to www.nasa.gov] , for our calculation we take lower number.

angle between Earth - Sun - Projected Ison path
atan(Se/Ss) = atan(6.3 x 10e10 / 1.5 x 10e11) = atan(0.2625) = 14.7 degrees

This is how much the course of Ison or one of its debrees must be changed in order to hit the Earth.

The speed we need to push Ison in perpendicular vector towards the Earth
V = Se/T = 6.3 x 10e10 / 2.4 x 10e11 = 2.6 x 10e4 = 26000 m/s

This is how much energy needed to do that:
E = mVxV/2 = 7 x 10e12 x 6.76 x 10e8 / 2 = 2.4 x 10e21 Joels

(1 kiloton of TNT equals to 5 x 10e12 Joels so we need
2.4 x 10e21 / 5 x 10e12 of kilotons = 4.8 x 10e8 kilotons = 30,000,000 Hiroshima bombs)

It looks a lot but considering total Kinetic energy of Ison:

8.6x8.6x 10e8 x 7 x 10e12 / 2 = 259 x 10e20 = 2.6 x 10e22 Joels = 5.2 x 10e9 kilotons = 325,000,000 Hiroshima bombs

we need only 9% of the total Ison energy to be redirected in order to change the course towards the Earth.
It does not look a lot.

Let's take only small chunk of Ison (we don't need the full comet for the disaster. For example for one Million of Hiroshima bomb we need 1/325 of Ison's mass thus it is enough to redirect 9%/325 = 0.028% of the total Ison energy to change the course of this chunk.
Remember we used lowest mass estimation. So the number can be even less.

Astromut and other experts!
Am I wrong? If yes show where.
 Quoting: Sergman


Op I checked the math and it looks all good to me.

It still won't hit earth though, because there is nothing that could redirect 9% of ison's energy.

What are you thinkincondidered
 Quoting: Anonymous Coward 50892049

 Quoting: Anonymous Coward 17415392


There's one other thing that is not being taken into account here, the original calculations for IsonS closest point to earth was December the 16th. It now has been recalculated by Nasa to be December the 26th, which means that Uson has had time to travel a lot closer to Earth.
Ison was originally estimated to miss earth by 40 million miles, Based on the above new Nasa estimate I have done some calculations myself and believe that Ison will now miss earth by 25 million miles, now couple this with OP's thread and it seems that Ison is going to be a lot closer to earth than we are being told
isonTards
User ID: 50931536
United States
12/02/2013 10:02 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
For years the flight of things launched from Earth were all done long hand math by a few mathematicians expert in orbital mechanics, a offshoot of celestial mechanics. They did not use computers to aim and time launches for the slingshots through the solar system.
isonTards
User ID: 50931536
United States
12/02/2013 10:08 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
After seeing some of the Black Friday videos, I guess the gov is right about the whole place falling into chaos if word was giving out about an incoming space rocks disaster. Better to just leave it to after the fact spin and bs.
Anonymous Coward
User ID: 50926203
United States
12/02/2013 10:26 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
I am not an astronomer but have basic knowledge of Newton physics. My goal here is to estimate how much energy we need in order to change the course of Ison so it will hit the Earth.

So let's start.

t: it takes 28 days for ISON to reach the Earth from Sun (2.4 x 10e6 sec)

Se: closest approach to the Earth 63,000,000 km (6.3 x 10e10 m)

Ss: distance from Earth to Sun: 149,600,000 km (1.5 x 10e11 m)

Vi: speed of Ison 86000 m/s = 8.6 x 10e4 m/s

m: estimated mass 7,000,000,000 kg (7 x 10e12 g) to 7,000,000,000,000 kg (7 x 10e16 g) from [link to www.nasa.gov] , for our calculation we take lower number.

angle between Earth - Sun - Projected Ison path
atan(Se/Ss) = atan(6.3 x 10e10 / 1.5 x 10e11) = atan(0.2625) = 14.7 degrees

This is how much the course of Ison or one of its debrees must be changed in order to hit the Earth.

The speed we need to push Ison in perpendicular vector towards the Earth
V = Se/T = 6.3 x 10e10 / 2.4 x 10e11 = 2.6 x 10e4 = 26000 m/s

This is how much energy needed to do that:
E = mVxV/2 = 7 x 10e12 x 6.76 x 10e8 / 2 = 2.4 x 10e21 Joels

(1 kiloton of TNT equals to 5 x 10e12 Joels so we need
2.4 x 10e21 / 5 x 10e12 of kilotons = 4.8 x 10e8 kilotons = 30,000,000 Hiroshima bombs)

It looks a lot but considering total Kinetic energy of Ison:

8.6x8.6x 10e8 x 7 x 10e12 / 2 = 259 x 10e20 = 2.6 x 10e22 Joels = 5.2 x 10e9 kilotons = 325,000,000 Hiroshima bombs

we need only 9% of the total Ison energy to be redirected in order to change the course towards the Earth.
It does not look a lot.

Let's take only small chunk of Ison (we don't need the full comet for the disaster. For example for one Million of Hiroshima bomb we need 1/325 of Ison's mass thus it is enough to redirect 9%/325 = 0.028% of the total Ison energy to change the course of this chunk.
Remember we used lowest mass estimation. So the number can be even less.

Astromut and other experts!
Am I wrong? If yes show where.
 Quoting: Sergman


ok
good math

but theres something abit weird about saying 'we need it move'
.....no WE dont need or want it to move
it will WIPE US OUT!!
 Quoting: Shadow Beam


No, we DO need it to wipe us out. Humans are a cancer on this planet. We need civilisatoin to start over, this one is completely f*cked.
 Quoting: Anonymous Coward 3122434



No YOU are wrong,we need complete wipeout, the ratio of good/evil and so would be the same with a partial wipeout, nothing gained at all, it must be total to change anything.
also the evil with all the resources will probably survive in greater ratio than above. it will only be worse than now.
Krystle|Ann

User ID: 49621846
United States
12/02/2013 11:30 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
...


Op I checked the math and it looks all good to me.

It still won't hit earth though, because there is nothing that could redirect 9% of ison's energy.

What are you thinking?
 Quoting: Anonymous Coward 50892049


...


Op I checked the math and it looks all good to me.

It still won't hit earth though, because there is nothing that could redirect 9% of ison's energy.

What are you thinkincondidered
 Quoting: Anonymous Coward 50892049

 Quoting: Anonymous Coward 17415392


There's one other thing that is not being taken into account here, the original calculations for IsonS closest point to earth was December the 16th. It now has been recalculated by Nasa to be December the 26th, which means that Uson has had time to travel a lot closer to Earth.
Ison was originally estimated to miss earth by 40 million miles, Based on the above new Nasa estimate I have done some calculations myself and believe that Ison will now miss earth by 25 million miles, now couple this with OP's thread and it seems that Ison is going to be a lot closer to earth than we are being told
 Quoting: Anonymous Coward 17415392


NASA doesn't have any fricking idea at all of what the hell is going on with that undead zombie thing.
 Quoting: Littlefeather


Yet people wonder why so many freak out or try to come up with their own conclusions..
:cpl3:
:rose:Power, Corruption and Lies..
Much more than just the title of an album.
The year was 2081, and everyone was finally equal.KV :rose:
Anonymous Coward
User ID: 35657107
Canada
12/02/2013 12:01 PM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
T1
s E Diff btw T1&T2
25723160 74109404 S E Percentage of movement to earth, based on movement away from sun
41397414 119267524 -1205 826 -69%
-1940 1330
T2 17,632,639.14 Distance from earth
S E
25721955 74110230
41395474 119268854




Your distance to earth is wrong. It's going to be much closer then you figured, meaning the chances go up significantly.
Anonymous Coward
User ID: 35657107
Canada
12/02/2013 12:02 PM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
T1
s E Diff btw T1&T2
25723160 74109404 S E Percentage of movement to earth, based on movement away from sun
41397414 119267524 -1205 826 -69%
-1940 1330
T2 17,632,639.14 Distance from earth
S E
25721955 74110230
41395474 119268854




Your distance to earth is wrong. It's going to be much closer then you figured, meaning the chances go up significantly.
 Quoting: Anonymous Coward 35657107


T1
s E
25723160 74109404
41397414 119267524

T2
S E
25721955 74110230
41395474 119268854


Diff btw T1&T2
S E
-1205 826
-1940 1330

Percentage of movement to earth, based on movement away from sun
-69%

17,632,639.14 Miles Distance from earth
Anonymous Coward
User ID: 46146650
United States
12/02/2013 12:09 PM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
WTF is a JOEL? It's certainly not a unit of energy!
Sergman  (OP)

User ID: 43941380
Canada
12/02/2013 04:53 PM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
I checked this matter in the biggest Russian astronomer forum. They say the kinetic energy can't be used to change the course. The only energy that can do that is explosion caused by overheated core. And apparently it is not enough to move the parts with 26 km/s from the comet. So according to them the doom is off.
:bdance:
Dr. AstroModerator
Senior Forum Moderator

User ID: 4211721
United States
12/02/2013 05:01 PM

Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Here's the real math on how much of the comet's mass it would take to propel the remaining mass to earth. Let's be super generous, let us assume that the volatiles of the comet will jet out in exactly the right direction to send the maximum possible remaining mass to earth, thus the comet's entire mass of volatile ices can be used as "fuel" to provide the thrust needed to send it to earth. That is the ultimate in generous assumptions. The question is then how much would remain to reach earth if that were the case. It would take over 57000 m/s delta-V, 57 km/s, to send any fragment of ISON to earth at perihelion. Furthermore, the delta-V would have have to push the comet in a sunward direction.
[link to imageshack.us]
That is the delta-V that must be achieved the volatile ices in the comet. Given an "exhaust velocity" of around 900 m/s for a comet (Combi et al 1997 [link to link.springer.com] ) we can calculate how much of the comet would have to act as "volatile fuel" and how much of it would remain to reach earth. Let's be extremely generous, ridiculously so. Let's say ISON is on the "friggen huge" range of comet nucleus sizes and has a diameter of 50 km, similar to Hale-Bopp. It's not that big, but for the sake of being generous to this example, let's just pretend it is. Let's also assume it is at the top end of the range of comet density, 1.2g/cm^3. It would therefore have a mass of about 7.854 x 10^16 kilograms. In order to deliver 57 km/sec of delta-V, all but about 0.0000000000245 kg of the comet would have to be "fuel" and would never reach earth. That is because delta V = Exhaust velocity * ln(total mass/final[payload] mass) The "payload fraction" that reaches earth would have a whopping mass of 0.0000000000245 kg.

In terms of more realistic numbers, comet separation velocities of major fragments are in the tens of m/s, orders of magnitude too small to send any to earth:
[link to www.lpi.usra.edu]
astrobanner2
Sergman  (OP)

User ID: 43941380
Canada
12/02/2013 08:00 PM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
I checked this matter in the biggest Russian astronomer forum. They say the kinetic energy can't be used to change the course. The only energy that can do that is explosion caused by overheated core. And apparently it is not enough to move the parts with 26 km/s from the comet. So according to them the doom is off.
 Quoting: Sergman


well, then, you'll be giving us the URL for that "Russian Astronomer Forum" then, right?
 Quoting: Littlefeather


Enjoy

[link to www.astronomy.ru]
:bdance:
Sergman  (OP)

User ID: 43941380
Canada
12/02/2013 08:03 PM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
here is google translation of one of the explanations what exactly happened and why we see what we see:

------------

I would like to draw attention to the following points calculators .

Before perihelion coma of comet shone brightly , as there shone volatile component . Coma diameter was D. Once the volatile component blew out of the coma by the radius vector , so shine coma plummeted , and the light is no longer coma and pseudokernel , which resulted in a change in the form of the head of the comet - a ball of it turned into an island . Dust at the time was just a little noticeable.
But if you look closely at the animation of "gray pictures " in the subject , it would appear that the animation "gray pictures " conveys the fact that the particles after the collapse of " flying in the pipe diameter D". This led to the fact that the comet's orbit was " highlighted " the dust component is in the form of a tube , like a coma continues to exist , but without volatile component. But volatile component entirely blown out of the pipe diameter D to the radius vector . Thus, the fan-shaped tail began to resemble a bird feather , where the rod pen - pipe and feather fluff , it blows the volatile component .

Hence it is clear that time was a lot of fan-shaped tail widths along the length of the sun , the dust particles flew " in the pipe " behind pseudokernel (which by that time has shattered ) , distributed along the length of the diameters of the sun for many ( millions of miles ) For those millions of kilometers diameter of the "tube " practically unchanged , that is not just flying orbit fine dust and decent weight pieces that could not be blown by the wind from the pipe . Hence, by not flying pipe micron dust , and most natural micro- comet. There were millions , and departed from each tail in the radius vector , like hair . These millions of tails formed veeropodobny tail.

From all this, making a very important conclusion - as the diameter of the pipe containing microcomets not changed , the core of the explosion was not, as the pipe would have the kind of slightly divergent cone. There was a discrepancy on the micro- comets orbit under the action of gravity, but it was very little , and on the corners " in degrees " it does not even go .

Ie animation "gray images " clearly indicates that do the calculations " of the explosion " , "Rate ", " on the corners of fragments " is simply meaningless - it has nothing in reality. As debris flew in a tight group in the pipe , so close group passed by her, so close group of her and walked out. The name of this pipe - Orbit .
:bdance:
Sergman  (OP)

User ID: 43941380
Canada
12/02/2013 08:30 PM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Here's the real math on how much of the comet's mass it would take to propel the remaining mass to earth. Let's be super generous, let us assume that the volatiles of the comet will jet out in exactly the right direction to send the maximum possible remaining mass to earth, thus the comet's entire mass of volatile ices can be used as "fuel" to provide the thrust needed to send it to earth. That is the ultimate in generous assumptions. The question is then how much would remain to reach earth if that were the case. It would take over 57000 m/s delta-V, 57 km/s, to send any fragment of ISON to earth at perihelion. Furthermore, the delta-V would have have to push the comet in a sunward direction.
[link to imageshack.us]
That is the delta-V that must be achieved the volatile ices in the comet. Given an "exhaust velocity" of around 900 m/s for a comet (Combi et al 1997 [link to link.springer.com] ) we can calculate how much of the comet would have to act as "volatile fuel" and how much of it would remain to reach earth. Let's be extremely generous, ridiculously so. Let's say ISON is on the "friggen huge" range of comet nucleus sizes and has a diameter of 50 km, similar to Hale-Bopp. It's not that big, but for the sake of being generous to this example, let's just pretend it is. Let's also assume it is at the top end of the range of comet density, 1.2g/cm^3. It would therefore have a mass of about 7.854 x 10^16 kilograms. In order to deliver 57 km/sec of delta-V, all but about 0.0000000000245 kg of the comet would have to be "fuel" and would never reach earth. That is because delta V = Exhaust velocity * ln(total mass/final[payload] mass) The "payload fraction" that reaches earth would have a whopping mass of 0.0000000000245 kg.

In terms of more realistic numbers, comet separation velocities of major fragments are in the tens of m/s, orders of magnitude too small to send any to earth:
[link to www.lpi.usra.edu]
 Quoting: Dr. Astro


Astro! Finally a man with knowledge.
Here is my question for you.
So we can't use kinetic energy of the comet. We agree that the material of the comet can propel the comet or part of it. Let's assume for simplicity that the comet is divided to two parts. One of mass m1 (that will fly down relative to the pass in order to hit the Earth), another of mass m2 that will propel m1. To keep the momentum

m1 x V1 = m2 x V2
and also
m1 + m2 = m

we know V1 = 5.7 x 10e4
V2 = 9 x 10e2

thus:

m1 = m2 x V2 / V1 = 0.01578 x m2
m2 = 63 x m1

In other words in order to throw one tone chunk with a speed 57 km/s you need 63 tons of material. To propel it. Not sure how you came up to your tiny number.

Of course my calculation is not precise because the propelled chunk also carries the "fuel"
:bdance:
Anonymous Coward
User ID: 50980918
Germany
12/03/2013 04:54 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Your way of calculation is correct, but the numbers not.
The mass is wrong.
Sergman  (OP)

User ID: 43941380
Canada
12/03/2013 05:26 AM
Report Abusive Post
Report Copyright Violation
Re: Can ISON hit the Earth? WARNING math inside
Your way of calculation is correct, but the numbers not.
The mass is wrong.
 Quoting: Anonymous Coward 50980918


It does not matter anyway. The idea to use kinetic energy is wrong. The bottom line: the comet will not hit the Earth.
:bdance:





GLP