Fun but dangerous

[Pilot7893]

Ok, imagine this. Ceres has miraculously missed Earth, but inserted itself into LEO. Although it makes flight up there difficult, here's something fun about it. Every time it passes overhead, there is a gravitational surge pulling up, so you briefly float up into the air!:rofl:

 

[pete.dakota]

Ok, imagine this. Ceres has miraculously missed Earth, but inserted itself into LEO. Although it makes flight up there difficult, here's something fun about it. Every time it passes overhead, there is a gravitational surge pulling up, so you briefly float up into the air!:rofl:

I didn't know Ceres was on it's way to hit us in the first place . What are you talking about?

 

[Pilot7893]

I didn't know Ceres was on it's way to hit us in the first place . What are you talking about?

Just something fun to think about. Thank GOD it's not going to hit us!

 

[pete.dakota]

Just something fun to think about. Thank GOD it's not going to hit us!

It's in a perfectly stable orbit around the Sun. That's like saying 'Thank GOD Venus isn't going to hit us.'

It's a dwarf planet, not an asteroid.

 

[Quick_Nick]

Moon-Ceres collision would look really cool!... until it all falls towards Earth.

 

[tomek]

I don't think you'll feel any kind of significant gravity surge when it passes above you, you have 1/6 Earth gravity on Moon surface, and Ceres is like 1% Moon's mass. I also don't think it could enter LEO, because LEO is around 400km, and Ceres is like megameter in diameter, "Ceres in LEO" would mean it'd just roll on Earth's surface.

That assuming it wouldn't be torn apart by tidal forces and bombard the Earth with few thousand city-size fragments.

 

[pete.dakota]

I don't think you'll feel any kind of significant gravity surge when it passes above you, you have 1/6 Earth gravity on Moon surface, and Ceres is like 1% Moon's mass. I also don't think it could enter LEO, because LEO is around 400km, and Ceres is like megameter in diameter, "Ceres in LEO" would mean it'd just roll on Earth's surface.

That assuming it wouldn't be torn apart by tidal forces and bombard the Earth with few thousand city-size fragments.

I beleive Ceres is around 5% the mass of the moon. So, yes, it's gravity would not have any notable effects on Earth if, somehow, it was to wind up in LEO. It's around 960km in diameter.

 

[Pilot7893]

Thanks for crushing my foolish childish dreams, guys

 

[Cosmos]

Are you gonna be around in 2029? This should prove interesting.

http://en.wikipedia.org/wiki/99942_Apophis

 

[ryan]

I want to see Neptune hitting Pluto, that will be a site to see, but i think Neptune will win.

 

[tomek]

Neptune actively affects Pluto's orbit in such a way that they won't collide. And it wouldn't cause any major damage to Neptune even if Pluto would hit it. I mean, Neptune is a gas giant - dwarf giant perhaps, but still... What can you possibly do to a gas giant?

 

[ryan]

It would hit eachother in the next something thousand years i think, and thats what i said Neptune will win, but it could move Neptunes orbit.

 

[tomek]

Well, it already moves Neptune's orbit, if I remember correctly, it was discovered because of that. However, Pluto's mass is like 10000 times less than Neptune's, so even a collision wouldn't change Neptune's orbit too seriously. And I'm not sure why would they hit each other in next thousand years, they've got a pretty stable arrangement there http://www.orbitsimulator.com/gravity/articles/pluto.html

 

[ryan]

Well, it already moves Neptune's orbit, if I remember correctly, it was discovered because of that. However, Pluto's mass is like 10000 times less than Neptune's, so even a collision wouldn't change Neptune's orbit too seriously. And I'm not sure why would they hit each other in next thousand years, they've got a pretty stable arrangement there http://www.orbitsimulator.com/gravity/articles/pluto.html

But when you compare Neptune and Plutos orbit they cross eachother, each orbit they just miss eachother but thats in space distance which is very very long.

 

[pete.dakota]

But when you compare Neptune and Plutos orbit they cross eachother, each orbit they just miss eachother but thats in space distance which is very very long.

They only appear to cross when observing from above the ecliptic. Pluto can and only ever will be above Neptune as their orbits would appear to 'intersect' in your eyes. This is because when Pluto is at it's closest point to the Sun, and so, Neptune's orbit, it is also destined to be at the 'highest' point relative to the ecliptic, and so, will never hit Neptune.

 

[tomek]

Well, it already moves Neptune's orbit, if I remember correctly, it was discovered because of that.

I remember incorrectly. Neptune was discovered from perturbations of Uranus orbit, but Pluto actually wasn't (though erroneous estimate of Neptune's mass triggered the search for the ninth planet, which eventually resulted in locating Pluto). Pluto does not affect Neptune's orbit in any kind of significant way.

But when you compare Neptune and Plutos orbit they cross eachother, each orbit they just miss eachother but thats in space distance which is very very long.

If you actually download Tony's gravity simulator and take a look at it, you'll see they don't "just miss each other". When Pluto catches up with Neptune, it gets attracted and therefore accelerated prograde - which, as you should know from Orbiter, results in Pluto going to a higher orbit and actually slowing down because of that. Then, after a while, Neptune approaches Pluto from behind, which lowers Pluto's orbit and accelerates it. So Neptune actually kind of "repels" Pluto. Their relative velocities would need to be higher to have a chance to collide.

 

[Lunar Pilot]

Ratios

Even if their orbits crossed, your talking about Neptune, which is about 33,000 miles across, and then you have Pluto, which is almost 2000 miles across. It's like a very small marble hitting against a basketball. Still, it would produce a remarkable falling star, considering the amount of ice on Pluto.