Everything you need to know: Comet ISON in 2013

reply to post by ngchunter

Thank you.
Why I asked you this specific question was I read about gravity assist effect the other day and it crossed my mind whether its applicable to comets.

reply to post by ngchunter


Thanks for this reply. I just incorrectly told a friend that it may be possible ISON could break up and slow down and hit earth with pretty large pieces.

My estimations were unfounded. I appreciate being corrected.

zilebeliveunknown
reply to post by cody599

 

What is new here with Ison we didn't know before?

You may have known, I didn't


Thanks for the info OP.

zilebeliveunknown
reply to post by ngchunter

 

Thank you.
Why I asked you this specific question was I read about gravity assist effect the other day and it crossed my mind whether its applicable to comets.

Despite what you may have seen in the movie Star Trek IV, gravity "slingshots" or "gravity assists" within the solar system cannot be done using the sun (more or less). Since all the planets are orbiting the sun (really the solar system barycenter hence the words "more or less") you can't really do a gravity assist with the sun, only with the planets. Sure, the sun can be used to change course, but you end up leaving the sun with the same velocity relative to the sun you arrived at sans any maneuvering you do on your own (also sans any perturbations from planets). The same is not true of a hypothetical gravity assist using a planet. A planet has momentum relative to the sun (a LOT of it) and you can effectively steal a tiny piece of that momentum during a flyby and use it to increase your own orbital velocity.
www2.jpl.nasa.gov...
I rather like their train analogy. Imagine the sun is a bystander sitting at a train station and the planet is a train coming towards the station at a 100mph. A ball is thrown towards an oncoming train. The ball is thrown at 30mph, but the train is traveling towards the stationary sun at 100 mph. The stationary sun sees the ball initially traveling 30mph relative to it. It hits the train. The train saw the ball coming towards at a net velocity of 130mph - the velocity of the ball + the train. The collision is perfectly elastic, so from the train's perspective the ball bounces away from the train and is still going 130mph, the same velocity it had on approach. From the sun's perspective though the ball has just been accelerated by 100 mph. Where did that energy come from? It came from the train's momentum. Of course the train has a lot of momentum so you don't see the train detectably slow, but that's where the energy came from. If you bounced the ball off the stationary sun instead it wouldn't change its velocity relative to the sun like it did with the train.

reply to post by cody599


Here is a very compelling video of a Chilean Astronomer(Carlos Muños Ferrada) who talked about Ison. Before Nasa & the Washington Post ever brought it to our attention.This was back in1939 & he called it planet/comet,it doesn't follows your regular celestial rules. As to many people are adamant of certain celestial laws.
He also predicted multple earthquakes within hours of devastation.

sinais2012.blogspot.com...

www.youtube.com...

reply to post by GraciaEspn


It wouldn't be possible to detect ISON in 1939.

It's not possible for a celestial body not to follow celestial mechanics. If such an object were found, it would be sensational news everywhere. But we haven't seen such an object.

Hercolobus and Nibiru are constantly-perpetrated myths and hoaxes that have no basis in real science.

You cannot reliably and consistently predict earthquakes, but in many places on Earth they happen so often that you could name a date, and there would be a good chance that an eq will happen on that date.

Lastly, lots of astronomers (including the amateurs) are tracking and studying ISON, and it's precisely where it's supposed to be. It looks like a comet, quacks like a comet, and follows the same celestial mechanics as the rest of Solar System bodies.

P.S. Extraordinary claims require extraordinary evidence. If that astronomer of yours discovered something remarkable or unusual, the right course of action would be to share his findings with the astronomy community so that they could be verified by other astronomers, and anounced officially. I could post a blog or paper claiming I spotted a previously unknown planet in the Solar System, but unless it's confirmed by other astronomers, my findings could be completely made-up, or caused by an error.

Cheers for that. I'm sincerely hoping Ison puts on a good show, but I suspect it will be another damp squib.

But hey, not long to wait now until we find out.

I bet if it's impressive it just rains every night so we don't see it.

originally posted by: GraciaEspn
reply to post by cody599

 

Here is a very compelling video of a Chilean Astronomer(Carlos Muños Ferrada) who talked about Ison. Before Nasa & the Washington Post ever brought it to our attention.

He didn't talk about ISON, and what he did talk about was utter nonsense which contradicted itself. He claims "Hercolubus" orbits between the sun and a "dead star" (probably playing off people's ignorance thinking a highly eccentric requires masses at both foci instead of only one) and that the distance of the dead star from us is 32 billion km. He says the velocity of this object magically INCREASES when it's between the "dead star" and our sun to 300 km/s. At that rate it would complete the journey between the "dead star" and our sun in... 3.38 years. Even at the slowest quoted speed of 76 km/s which is the speed it supposedly has at perihelion with our sun before it accelerates again on its way back to the dead star, it would get here from the "dead star" in 13.3 years in direct contradiction to the 13000 years he claims it has been since it was here last, and that's if it maintains the slowest speed he gave and never reaches the 300 km/s velocity he gave!

This was back in1939 & he called it planet/comet,it doesn't follows your regular celestial rules. As to many people are adamant of certain celestial laws.

Ah, so it doesn't because he said it doesn't. Nice circular logic. The most likely explanation is that he doesn't even know how to compute orbits properly and follow the laws of physics, so he just created a claim which he says doesn't follow the laws of physics so that no one can claim he's wrong based on verifiable laws of physics. He's trying to create an unfalsifiable belief but he was so incompetent that his own claim is self-contradicting. And don't even get me started about his supposed "earthquake prediction" in a newspaper article that is actually about an "aerial route to strait of magellan and time changes" "by carlos munoz ferrada, pilot of the merchant marine." That's what the article actually says, they even flash a picture of it in the video you refer to and just lie about what it says hoping you don't notice. So he wasn't an astronomer, he wasn't writing an article about predicting an earthquake, and his claimed planet's distance and speed completely invalidate his own claim of how often it passes through the solar system by orders of magnitude.