Countdown to Pluto

originally posted by: KrzYma
a reply to: Arbitrageur

One reason a Pluto orbit would take more fuel than say a Saturn orbit, is that Pluto has a lot less mass, so less gravity, meaning you'd have to slow the spacecraft down a lot more compared to a Saturn orbit, ....

?? what ?

Gravity is acceleration, bigger mass more force...
a body falling into a gravity field accelerates, so it needs more energy to stop compare to lower mass

you talk it backwards !!!

A smaller object like Pluto needs very little orbital speed. New Horizons is currently moving at an incredible speed. It would have to slow down considerably in order to be captured by Pluto's gravity. New Horizons isn't simply falling into Pluto's gravity well. It is actually moving at a solar escape velocity, so unless it has lots of extra fuel, it won't slow down and will eventually leave the Solar System. en.wikipedia.org...

?? what ?

Gravity is acceleration, bigger mass more force...
a body falling into a gravity field accelerates, so it needs more energy to stop compare to lower mass

you talk it backwards !!!

Saturn's gravitational field is much stronger than that of Pluto, so you do not need to reduce your velocity as much in order to be captured by it. Going into orbit around Pluto when you are already travelling beyond solar escape velocity would require a huge amount of fuel, and a significantly greater reduction in velocity.

Very cool.

Maybe, just maybe, New Horizon will give the exploration/exploitation of space the boost it needs since the glory days of the Apollo Lunar missions...

I know I'll be watching the pictures come in... going "ooooh, aaahhh" a lot.

a reply to: wildespace
a reply to: Mogget

I see your point !

Of course, the real problem is relative velocity. New Horizons is travelling much faster relative to Pluto than (for example) Cassini was relative to Saturn.

I may be way off so if I am say so...

I would think this probe might add some weight, or remove, with regards to a larger body somewhere in the outer solar system.

originally posted by: Xcathdra
I may be way off so if I am say so...

I would think this probe might add some weight, or remove, with regards to a larger body somewhere in the outer solar system.

Not quite sure I understand what you mean by "add some weight, or remove" ?

Could you explain a little bit more what it is you mean?

originally posted by: Xcathdra
I may be way off so if I am say so...

I would think this probe might add some weight, or remove, with regards to a larger body somewhere in the outer solar system.

If by "weight" you mean "evidence" for another large body, I don't think New Horizons has the instruments on board in order to find another large body out there.

Maybe if it finds some irregularities in Pluto's orbit, that may lead to the possibility of another large body out there, but I think astronomers have been tracking Pluto long enough to have a very good idea about its exact orbit already.

My bad sorry..

Yeah I meant the probe might be able to shed light on the possibility of a large object existing out past Pluto.

a reply to: Xcathdra

As the probe swings by Pluto and it's moons, any effects of their gravity on the probe's flight path will be recorded, and that data will help further refine Pluto's mass.

That then can be compared to it's orbit (which is well documented), and if there are any thing that is pulling on it will show up better (IF their is anything that shows that).

So the flight data will either open up more theories, or it will be another nail in the coffin of any large bodies out past it.