Could Phobos Be Hollow? Flyby took no photo's.

reply to post by predator0187

I would say at first glance that this does look odd but I think this article leaves a lot of information out.

The spacecraft skimmed smoothly over the odd-shaped moon at just 67 km, the closest any manmade object has ever been. No images were taken from this flyby.

This does sound like a missed opportunity that is for sure, but there is more. This next explanation doesn't make much sense to me.

Instead all the instruments were turned off so that ground stations could listen for a pure radio signal of how Phobos "tugged" on the spacecraft.

I think this is where the writer of this article fails to correctly explain what is going on. How do radio signals make a "tugging sound" or in any way relate to a gravitational tug. I understand how observing the motions of the Mars Express spacecraft during a close flyby can reveal gravitational information about Phobos but what is the part about "pure radio signals" tugging on the spacecraft?

Originally posted by Mr Sunchine
Sorry for over reacting. I just find it hard to believe people when I read things like the Earth's moon is hollow or whatever in the solar system is hollow. Gravity wouldn't really allow for things to form in a hollow state on that scale.

I understand your skepticism, and I think this is good, but don't assume because this sounds incredible that it means it cannot be true. Skepticism works both ways, don't accept what sounds incredible without question yet don't deny it without question neither.

Previous flybys of Phobos have shown that it is not dense enough to be solid all the way through. Instead, it must be 25-35% porous. This has led planetary scientists to believe that it is little more than a ‘rubble pile’ circling Mars. Such a rubble pile would be composed of blocks both large and small resting together.

Porous means hollow in a manner of speaking. The theory that this is simply a "rubble pile" is a poor choice of words that fails to describe what is seen in previous images of this moon. The theory of this as a "rubble pile" comes form the data showing that it is semi-hollow or "porous" and I would argue against this assertion that it is a pile of rocks.
So it appears that the data is showing a partially hollow moon and the speculation is that this is a pile of rubble. Except the data for what it is and be skeptical of the speculations obtained from it.

Originally posted by
We really have very little insight into gravity, although we do have theories. Gravity is very misunderstood.

Gravitational forces can be predicted and measured with extreme precision. It is the source of the phenomena that is unknown, we know it has to do with mass, acceleration and distance but after that is remains a mystery.

I do not really believe the whole 'devil' thing either, but it is damn freaky to think about.

Although I have debated the whole concept of "Evil" and such in the past as a creation in the minds of humans I would like to point out that the names of the moons of Mars are Phobos and Deimos and this in itself has a very interesting history;

Both satellites were discovered in 1877 by Asaph Hall, and are named after the characters Phobos (panic/fear) and Deimos (terror/dread) who, in Greek mythology, accompanied their father Ares, god of war, into battle. Ares was known as Mars to the Romans.

Source-Wiki


What I do believe is that the naming of these moons was no accident. I strongly feel that there is a lot of history and myth tied to the moons of Mars. If the myths are not related to these two moons they they represent two other objects that accompanied (or were associated with) Mars in historical times. There are numerous ancient connections between the planet Mars and its moons with war, pestilence and destruction to the Earth and life.

As far as this being a lost opportunity there are more scheduled flybys to come.

This flyby was just one of a campaign of 12 Mars Express flybys taking place in February and March 2010...In the coming flybys, the Mars Express camera will take over, providing high resolution pictures of the moon’s surface.

[edit on 3/6/2010 by Devino]

reply to post by Devino


I don't know how much you know about gravity so if I say anything that offends you my apologies now.

Gravity is very misunderstood. Yes as far as motions of the planets we can predict where they are going to be but that about sums it up. They have had many spacecrafts do slingshot effects around rotating gravitational bodies and their calculations are wrong.

Also gravity is not understood on the Quantum level which, well, everything is Quantum because we are all made of quantum particles. Gravity has also not been understood on the macro level as well. We have invented this stuff called dark matter and energy that we are using to explain loop holes in our understanding of gravity.

Most of the anomalies in science right now consist of gravity, it is very misunderstood.

If you would like more information I would be willing to provide it in much more detail.

Pred...

Originally posted by Phage

To make the very sensitive measurements of Phobos' interior, all the data signals from the spacecraft will be turned off. The only thing that the ground stations will listen out for is the ‘carrier signal’ – the pure radio signal that is normally modulated to carry data.
With no data on the carrier signal, the only thing that can modulate the signal is any change in its frequency caused by Phobos tugging the spacecraft. The changes will amount to variations of just one part in a trillion, and are a manifestation of the Doppler effect – the same effect that causes an ambulance siren to change pitch as it zooms past.

This is a much better explanation of the mission and what is going on. Thanks Phage.

Originally posted by predator0187
I don't know how much you know about gravity so if I say anything that offends you my apologies now.

So far you have inspired me to reply to this thread and I thank you for that, no offense taken so far in the least.

They have had many spacecrafts do slingshot effects around rotating gravitational bodies and their calculations are wrong.

This is a good point but I think the failing has to do with a misunderstanding of accelerations that were not calculated into these predictions. Keep in mind that our Sun is accelerating as well as the Milky Way that effects everything inside the solar system. These minute gravitational anomalies might be accounted for if we take into consideration these motions, accelerations effect gravity.

Also gravity is not understood on the Quantum level which, well, everything is Quantum because we are all made of quantum particles. Gravity has also not been understood on the macro level as well. We have invented this stuff called dark matter and energy that we are using to explain loop holes in our understanding of gravity.

Another good point but again I think the failing is in the lack of consideration for outside accelerations. Of coarse the rotation of the Earth (which is considered an acceleration) does little to effect gravity but how about the rotation of the Milky Way galaxy, the galactic center and galactic spiral arms? These are all said to be accelerating at different rates.
Since our Sun is being accelerated along by a galactic rotating force then this most certainly effects the gravity of our star, planet, moon and everything else in the solar system. The force that accelerates mass effects gravity according to relativity but this is not considered in orbital motions as far as I know. More to my point I know of no measure of galactic rotational acceleration in figuring orbital mechanics and if I am wrong I would love to read about it.

Another point, and this is where I usually get into trouble, has to do with the concept of "particles". This is nothing more than a theory to help explain what is being observed. Particles do not exist outside of our imagination, they are rather a function of waves.

Most of the anomalies in science right now consist of gravity, it is very misunderstood.

Funny, I look at it the other way around. Gravity is the one thing in science that is understood, at least in its predictions and measurements. The myriad of so called anomalies come about from attempts in trying, and failing, to explain theories such as the big bang and concepts like particles.
Accept the evidence and data as it is and question said theories and factitious concepts not the other way around.

Originally posted by Devino
So far you have inspired me to reply to this thread and I thank you for that, no offense taken so far in the least.

Good, I am glad to hear that because I enjoy talking about physics, it's what makes me think.

This is a good point but I think the failing has to do with a misunderstanding of accelerations that were not calculated into these predictions. Keep in mind that our Sun is accelerating as well as the Milky Way that effects everything inside the solar system. These minute gravitational anomalies might be accounted for if we take into consideration these motions, accelerations effect gravity.

I agree, but no one really knows the motion of the galaxy, yet. I think that it will help in our understanding in physics, but that is something that is misunderstood.

Another good point but again I think the failing is in the lack of consideration for outside accelerations. Of coarse the rotation of the Earth (which is considered an acceleration) does little to effect gravity but how about the rotation of the Milky Way galaxy, the galactic center and galactic spiral arms? These are all said to be accelerating at different rates.
Since our Sun is being accelerated along by a galactic rotating force then this most certainly effects the gravity of our star, planet, moon and everything else in the solar system. The force that accelerates mass effects gravity according to relativity but this is not considered in orbital motions as far as I know. More to my point I know of no measure of galactic rotational acceleration in figuring orbital mechanics and if I am wrong I would love to read about it.

I do agree. But what I was saying is that we are no where near knowing these ideas. It is hard for physics to maybe possibly admit that the cosmological constants could have been different in the past.

They have tried to explain this acceleration of 'everything' by using the term 'dark matter/energy.' I think this is a fallacy and it is just gravity not fully understood.

Everything is one force, that is what everyone is working on figuring out right now, but because of our little understanding of gravity we are stuck with anomalies. If we had a fuller understanding we would have already had a TOE.

Another point, and this is where I usually get into trouble, has to do with the concept of "particles". This is nothing more than a theory to help explain what is being observed. Particles do not exist outside of our imagination, they are rather a function of waves.

No, I understand what you are saying. But, what they predict in String theory is that all of the 'particles' we see are wave functions of a string that is at the Planck level. Our technology has not been able to get even close to that level.

Funny, I look at it the other way around. Gravity is the one thing in science that is understood, at least in its predictions and measurements. The myriad of so called anomalies come about from attempts in trying, and failing, to explain theories such as the big bang and concepts like particles.
Accept the evidence and data as it is and question said theories and factitious concepts not the other way around.

I agree numbers do not lie and that is our best way of looking at things. I am all for a overhaul in physics I think it is long overdue, we need a new way of thinking and understanding our world because we have puzzle pieces that are not fitting together right.

Thanks for an intelligent discussion.

Pred...

reply to post by Devino

What I do believe is that the naming of these moons was no accident.

Indeed not. They were discovered and named in 1877 by an astronomer who knew his Greek mythology, as most did in those times when knowledge of the classics was part of a decent general education. Generally speaking, planets tend to have names from Roman mythology and natural satellites from Greek mythology, though I doubt it's a hard-and-fast rule.

I strongly feel that there is a lot of history and myth tied to the moons of Mars.

Unlikely. The discoverer of the moons of Mars, Asaph Hall, just gave them the most obvious possible names.

There are numerous ancient connections between the planet Mars and its moons with war, pestilence and destruction to the Earth and life.

The connexions can hardly have been very ancient, since the moons were unknown to mankind before 1877.