Real question about Elenin

1.) How does Elenin survive these temps intact? Wouldn't it also become super-heated and simply dissipate?
It does dissipate. Slowly.

The hottest places on the surface of Mercury get that hot after being exposed to the Sun for months. The day is 178 Earth days long.

Comets are more reflective, reducing insolation.
The outer layer sublimates taking away heat from the surface. This forms the coma which itself reflects sun light.
We've seen comets dive straight into the Sun while still being in one piece, they are just that fast and sturdy.
We've seen other comets not even that close to the Sun break up.
They are all different.

2.) If Elenin has such a low mass, as NASA claims, what makes it return to the inner solar system at all? Why doesn't it just shoot out into deep space forever?
Its kinetic energy ((mass x velocity squared / 2) does not exceed its gravitational potential.
It takes work to move higher, i.e. to move away from the Sun. It will slow down as it gets higher.
At some point its outward speed will be zero and it will start falling back.

Google those terms, and escape velocity. I'm sure there are people out there who can explain it a lot better then I could.

I mean, clearly it goes way, way out into space so how far out does the suns gravitational pull effect stuff?
In theory it never stops.
The further away from the Sun the smaller the force gets, it never reaches zero.
It some point it gets overtaken by the pull from other stars. About 2 lightyears out.

Orbits of many millions of years more then a lightyear out are certainly possible but might not last long.
Every ten million years or so a star passes close by (i.e. within 2 ly), perturbing it.
That might cause it to be flung out, becoming a rogue, or to move closer to the Sun.

Why aren't our Voyager units returning towards the sun? surely they are traveling slower than Elenin and gravity would act the same on them as on other objects right?
The further away from the Sun the smaller the gravitational pull is, so it requires less speed to escape.
Comet Elenin has yet to climb out of the well.
At that distance from the Sun it will be slower then the Voyagers.

3.) One last question. If it is the Suns gravity pulling Elenin into the inner solar system than why doesn't it just pull it right into it's core? Isn't this where the "heart" of its gravitational force originates?

It started out with sideway speed. That speed doesn't change, there is nothing to change is.
It falls towards the Sun but misses, like every other object orbiting it, including planet Earth.
Perhaps best to start with Newton's Cannon.


Indeed.

The really stupid don't ask questions. They think they already know it all.


Last Edited by Halcyon Dayz, FCD on 07/28/2011 12:43 AM