216 Kleopatra -Asteriod has its own moons?!

Originally posted by CLPrime
"Moon" is the name given to any natural satellite...any object that orbits another and is not artificial. This is regardless of size. Asteroids have moons just as planets do.

Cool thanks CLPrime. I didnt see for sure if these two moons are orbiting or following. And that is what makes me think if this Asteriod is going in a more straight like path due to it not having any other celestial body to cause an orbit, then how could the moons orbit it instead of trail it. Further are any of the Asteriods that fit the 2% moving with their moons in same pattern if not, THEN WHY??
Thanks

reply to post by Ophiuchus 13


Think of it this way: the Earth is moving through space at 30 km/s. Kleo is moving at 18 km/s. The Earth has a moon in a very stable orbit. Certainly, Kleo's moons can maintain stable orbits.

Also, it's more likely that the moons are in orbit rather than just "trailing". Things tend to orbit, because the lack of an orbit indicates a lack of motion when things formed...and things are always moving.

reply to post by CLPrime


I can understand that but the Earth is also in orbit of the Sun. the Asteriod has no parent as I will call it to follow, its just moving. Thats why I wonder is this normal pattern of the 2% mentioned or something out of the norm..

reply to post by Ophiuchus 13


Asteroids orbit the sun just as the earth does. If the moons were just trailing the primary, then they wouldn't be considered to be in orbit as their relative velocities would be same. That would mean they weren't moons at all, but separate asteroids with coincident orbits.

reply to post by CLPrime


I also love math and physics, and often wish I had gone the academic route. I was a bit disappointed with calculus. At what point do we start moving on to the next level above calculus, and start taking a serious look at the critical aspect of proportion and precision. The concept of 'zero' needs to be taken in a more realistic approach, and looked at as simply a designated point of origin, not as an abstract concept of nothing. Zero should be considered as a null point of origin, and infinity simply as off scale, same as the square root of neg 1.

I had thought that density had a great deal to do with the force of gravity. The more dense a planet, the greater its gravitational pull. Earth has an iron core, so it has a strong gravitational pull, while Mars, which is less dense, has a much weaker gravitational pull.

It seems that Kleo would most likely be a giant magnet, considering its shape. That must create all kinds of strange anomalies.

reply to post by Ophiuchus 13


Kleo orbits the sun just as the Earth does, and not much farther out. This has nothing to do with whether or not Kleo's moons orbit it or trail it.

180 minor planets have moons. As far as I know (and I really should know), not one of these cases involves moons that simply "trail" rather than orbit. In fact, I can't envisions a situation that would allow a satellite (whether external debris or debris from the asteroid itself) to be captured by the asteroid and trail it instead of orbit it. The very nature of gravitational capture is a "free-fall" scenario, where the object is pulled in toward the asteroid but is moving with enough transverse velocity to keep it from impacting. This set-up leads to a stable orbit. For an asteroid to pick up a trailing object would require no 'free-fall versus transverse velocity' effect, which would put the object directly in the path of the asteroid. This would lead to an impact and, obviously, no orbit.

Originally posted by poet1b
reply to post by CLPrime

 

I also love math and physics, and often wish I had gone the academic route. I was a bit disappointed with calculus. At what point do we start moving on to the next level above calculus, and start taking a serious look at the critical aspect of proportion and precision. The concept of 'zero' needs to be taken in a more realistic approach, and looked at as simply a designated point of origin, not as an abstract concept of nothing. Zero should be considered as a null point of origin, and infinity simply as off scale, same as the square root of neg 1.

My experience with Calculus is an interesting one. By junior high, I had taught myself pre-Calculus. Further into high school and I knew differential calculus and had a basic working knowledge of integration. Then, university Calculus came along. I failed it three times.
It became too abstract for me, for the reasons you indicate. It needs to be more rooted in physical reality and common sense rather than abstract laws and numbers.

I had thought that density had a great deal to do with the force of gravity. The more dense a planet, the greater its gravitational pull. Earth has an iron core, so it has a strong gravitational pull, while Mars, which is less dense, has a much weaker gravitational pull.

Density has nothing to do with gravity, other than the fact that density and volume give mass, which has everything to do with gravity. Gravity is the result of the presence of inertia. Mass is an illusion caused by inertia. Gravitation, then, is proportional to mass.
The denser a planet (given a constant volume), the more mass it has...therefore, it digs a deeper gravitational well. The connection between density and gravity is indirect.

It seems that Kleo would most likely be a giant magnet, considering its shape. That must create all kinds of strange anomalies.

I'm not sure how Kleo's shape indicates magnetism. I would certainly agree with it being magnetic, but can you elaborate on the shape aspect?

reply to post by CLPrime


Glad you see what I mean by our current state of mathematics.

Ok, I get what you mean, it is mass that is the critical factor, not just density, density is factor, but only a factor. I think you are referring to gravity being the result of a warp in space created by time and mass, or something along those lines. It has been a while since I have looked at the theory.

My point about the shape of Kleo being relative to its magnetic properties is more of an instinctive concept. The shape of Keo being polar, leads more readily to greater influence of magnetic fields, which are polar. This concept I have kind of hooked upon might not have any basis at all when it comes to the physics of planetoids. My concept is that a polar shaped planetoid would be less subject to flips in magnetic polarity, or at least polar drift.

While electrical charge is not limited to the existence of physical mass, from my understanding, a magnetic field does require the existence of a physical mass. Maybe I am wrong about this. In a polar shaped body, the drift of the polar fields is restricted by the concentration of mass are each end of the polar body. While in a spherical shaped body, the poles can drift continuously around the circular mass.

reply to post by nataylor


Got you thanks

Ok ALL I may be stepping away for some time. I really appreciated the comments posted and would like to see more I will check back later and respond if not to far out of original post time.

You might find this interesting: en.wikipedia.org...

Any object has its own gravity. Any object that has a Hill sphere outside of its own radius should be able to have moons orbiting it.

This asteroid is just 1.2 km across en.wikipedia.org...
but it has a moon orbiting it every 16 hours at a distance of 2.6 km.

Originally posted by poet1b
reply to post by CLPrime

 

Ok, I get what you mean, it is mass that is the critical factor, not just density, density is factor, but only a factor. I think you are referring to gravity being the result of a warp in space created by time and mass, or something along those lines. It has been a while since I have looked at the theory.

Yes, density is as much a factor as volume is. Mass (well...inertia) is what actually causes gravity.
And, ironically, I don't agree with Einstein's view of gravity, in General Relativity, as a warping of spacetime. I am using that terminology, because it's an easy way to get my point across, but, being the Quantum-based person I am, I believe that gravity is a result of some sort of QM effect, like the other 3 fundamental forces.

Regardless, the source of gravity is the same. And that source is mass/inertia (although, General Relativity adds momentum, in the case of otherwise massless particles, like photons).

My point about the shape of Kleo being relative to its magnetic properties is more of an instinctive concept. The shape of Keo being polar, leads more readily to greater influence of magnetic fields, which are polar. This concept I have kind of hooked upon might not have any basis at all when it comes to the physics of planetoids. My concept is that a polar shaped planetoid would be less subject to flips in magnetic polarity, or at least polar drift.

While electrical charge is not limited to the existence of physical mass, from my understanding, a magnetic field does require the existence of a physical mass. Maybe I am wrong about this. In a polar shaped body, the drift of the polar fields is restricted by the concentration of mass are each end of the polar body. While in a spherical shaped body, the poles can drift continuously around the circular mass.

If you're suggesting that the "dumbbell"-esque structure is caused by magnetism, I think it's more likely that its structure is explained by Kleo being the result of two asteroids impacting and fusing together.
If you're suggesting that the shape, itself, indicates a magnetic nature, then I still don't see it. Especially considering the above.
Now, I can see how such a shape could indicate a greater magnetic stability than a typical spheroid, like a planet, but it's a bit more complicated than that. The magnetism of an asteroid would be caused by the alignment of electrons within its metallic body, just like a regular magnet, albeit on a much larger scale. The magnetism of a planet is a result of the fluid dynamics of liquid metal at the core with respect to a solid inner core (the Dynamo Effect). Since the Dynamo Effect is based on the movement of fluids, the resultant magnetism is, itself, a bit fluid and subject to fluctuations and, occasionally, reversals. This could not happen with magnetic asteroids, since the source of the magnetic field in that case is much more stable. Asteroids could no more experience magnetic reversals than could a fridge magnet.

Also, electric fields and magnetic fields are two aspects of the same thing - the electromagnetic force. An electric field is generated by a changing magnetic field (like electrons moving through a wire). A magnetic field is generated either by a magnetically-charged particle (like most fundamental particles) or by a changing electric field. Thus, a changing electric field generates a magnetic field, and a changing magnetic field generates an electric field. This allows the combined electromagnetic field to be self-sustaining, even through a vacuum.
This is getting a bit off-topic, and, now that I'm done writing it out, I can't remember what my point with all of this was ...but, there it is. If I think of what my point was, I'll tell you.

ETA: Oh!! I remember. It was to show that, yes, you're right when you differentiate electric and magnetic fields according to what generates them...but to a point, considering the fact that they're two sides of the same coin.

I also meant to point out that, an electric field in one reference frame (such as a stationary one) can appear to be a magnetic field in another (such as a moving) reference frame.
The two are interchangeable.

Originally posted by randyvs
...Seriously is there a difference between minor planets and asteroids? This seems to widen the scope as far as gravity is concerned. Dosn't appear that mass has much to do with gravity after all.

Everything -- all matter -- has gravity. You have a gravitational effect on the stuff around you (albeit an imperceptible one).

An astronomical body does not need to be real large/massive to have a noticeable gravitational effect on the stuff around it. For example, Saturn's moon Daphnis is only 8 km (about 5 miles) wide. However, even with its small size, it has a gravitational effect on Saturn's rings, giving a pert of the rings a "wavy" structure:
www.airspacemag.com...

216 Kleopatra is a lot larger than Daphnis at 135 miles long. Even if it was a relatively average dense body, it would have a decent gravitational effect on medium-sized rocks near it (and some bigger rocks, like it's moons), considering what tiny Daphnis can do to at Saturn.

This is possibly the coolest astroid I've ever seen. It has a very cool shape and it's own satellites? I know someone's going to say that it's really a space ship/station.

Originally posted by CLPrime
As for it being magnetic, that's certainly possible. That would also add another force to hold onto those moons, if they're also magnetic (which they should be, if they're just broken-off bits of Kleo, herself).

Very good post although I would respectfully disagree with what you said above... magnetism does not help to keep large objects in orbit as far as I know.

Magnetism is a relatively strong force that works at relatively short distances

Gravity is a weak force that works at relatively large distances

The multipole electromagnetic fields are pretty dang weak. Think about it this way: Watch a compass needle. It doesn't snap into alignment with the Earth's magnetic field. It slowly meanders into alignment. The Earth's magnetic field averages 0.5 gauss on the Earth's surface. In comparison, the field of a small bar magnet at the boundaries of the magnet is about 100 gauss. It gets worse than that: the multipole fields drop as the inverse cube of distance. On planetary scales and larger, the gravitational force completely predominates the other fundamental interactions./ex]
Source: physicsforums.com

reply to post by C.H.U.D.


I was speaking hypothetically, in the case of an asteroid with an extremely strong magnetic field and likewise magnetic moons at a relatively close distance. Of course, I know of no such system in real-life, and, as you say, gravity is, by far, the predominant force over large distances.

reply to post by Ophiuchus 13


Ah this is just too cool, I am going to bed right now, but want to find this thread again in the morning. Asteroids with their own moons? Ah, what possibilities!!! Love the implications.

reply to post by CLPrime


Fair play. Thanks for the clarification.

reply to post by CLPrime


No, I don't think the dumbell, or dogbone shape was caused by magnetism.

I think the shape, with most of the mast on the ends lends itself to creating a more fixed type of magnet.

I suspect that gravity and magnetism are linked.

reply to post by poet1b


My QM mind agrees that gravity and EM are linked.
And, I think you're right, the larger ends could most definitely result in a more stable magnetic nature, assuming the asteroid is, in fact, magnetized. The fact that it appears to be metallic makes that last bit probable. If it is magnetic, that may have been a factor in causing two initial asteroids to collide and fuse together. Gravity can cause asteroids to collide, but the symmetry and the energy required to fuse cleanly like we see with Kleo suggests to me that the two asteroids may have been not just gravitationally attracted, but also magnetically attracted.

But, then, I would have to do the math on that. And, knowing me, I probably will...

EDIT: The math involved when dealing with dipoles is more than I'm willing to handle this late/early in the morning. Also, trying to estimate the magnetic field strength of a monopole asteroid is a frustrating task that I am, right now, giving up on. I must say, though, that the field strength of two asteroids would have to be relatively HUGE in order to be dominant over the gravitational attraction over a large distance (of, say, several hundred kilometers...enough distance to allow the two asteroids to gain enough momentum to fuse more efficiently than they would through purely gravitational attraction). That leads me to believe that, if the two pre-collision asteroids were magnetic, it probably had no part in their collision.

And, yes, I know that the affect of magnetism on Kleo's formation was entirely my idea. You have just witnessed the birth and death of a brain-fart.
That says nothing about whether or not Kleo is, now, magnetic.