Can anyone intelligently answer this?

Question

What is, specifically, a planetary magnetic field (as opposed to just any ol' magnetic field)?

Where do they come from?

What effect(s) do they have on a planet?

Answer 1

A planet's magnetic field forms a shield protecting the planet's surface from energetic, charged particles coming from the Sun and other places

Answer 2

umm isnt it just like a magnet? like something that attracts metal ? i dunno like  u know those fridge magnets isnt it like that? idk but ok if u find out enjoy it

Answer 3

Generally a planets magnetic field is generated by a planet's metallic or iron core acting as a dynamo -- and generating huge currents surrounding the planet-- Earth and Jupiter would be two examples--

http://csep10.phys.utk.edu/astr161/lect/...

http://hyperphysics.phy-astr.gsu.edu/Hba...

Answer 4

The region of a magnetic field associated with an astronomical object, ie a very dense object such as the Earth.

Planetary magnetic fields are also referred to as Magnetospheres.

The basis of formation of these magnetic fields is defined by the dynamo theory, too long to be mentioned here and needs a lot of explanation, but you can research it. In short, it mentions that these fields are formed from the presence of highly conducting fluids in the cores of planets and other physics-related effects (search for the Coriolis effect).

For example, in the Earth's core, a lot of iron is present which is a ferromagnetic material and combined with the above effect creates a magnetic field. Also electric currents flowing through space contribute to this whole magnetic field formation, it is really a big topic.

As for the effects, for Earth for example, it has an important function in shielding us from some of the energetic particles created by cosmic rays in space. The atmosphere above the Earth circulates them throughout the magnetosphere and thus protecting us. Those trapped particles are called Van Allen belts (search for Van Allen belt if you want more information on how it is formed).

Hope this helps.

Answer 5

Planetary magnetic fields are the magnetic fields that are generated by planets for themselves.

As has already been stated, magnetic fields are generated by moving currents.

You can generate a magnet by coiling a wiring and passing electricity thru it.

It the case of earth - the molten iron core is convecting and thus moving, and at the same time the earth spins, so the conducting molten iron is effectively in coils of current and thus we get a magnetic field.

Mars doesn;t really have one (it has a weak one frozen into surface rocks) because it is smaller and thus cooled faster and so doesn;t have a molten core.

Venus doesn;t have one because, although it probably does still have a molten core, it spins too slowly.

In the gas of the gas giants, the high densities make the internal gas compress into a state in which the hydrogen is liquid and behaves like a metal, so the same mechanism works.

As for what they do - charged particles from the sun (cosmic rays) are deflected by the magnetic field, so very few make it into the atmosphere and thus the magnetic field protects the atmosphere. Some get thru - especially at the poles (because of the shape of the magnetic field) and this is what causes aurora

I hope that is intelligent enough for you...

Answer 6

I don't think anyone can.  I mean, what is magnetism, exactly?

But magnetism is generated by moving electric fields.  The Earth's magnetism comes from movement of the hot iron at the Earth's core.  This magnetic bubble helps keep our atmosphere bound to the Earth, and shields us from certain kinds of radiation.

Answer 7

A magnetic field is something that is understood by man, but not explained.  The best explanation we have is when certain metallic elements align themselves in a row creating a polar filed.  Why magnetism actually occurs is still a mystery.

The magnetic field of Earth is created by a molten iron core.  Since magnetism forces itself apart when in contact with a similar polar contact (+/+ or -/-), we have a poles on the Earth.  Remember the old stereotypical magnets on Saturday morning cartoons shaped liked a horseshoe?  The two adjacent ends are opposites.  If they were similar in polarity, you would have an expensive horseshoe, not a magnet.  

Janet Jackson got it right in the 80's.  'Opposites Attract'

(dumb reference to a song)