ok this has been bugging me for a while now. if supposedly venus, earth, and mars had/have a molten core then why is earth the only one with a magnetic field. does it have something to do with plate tectonics and the moon.
Earth is the only terrestrial planet with a significant magnetic field because it is the only one that has all the ingredients: a conducting liquid, convection, and rotation. Venus, because of its lack of plate tectonics, lacks convection. Mars lacks a conducting liquid because its core solidified.
Many different ways to get a bike in the back of a truck. However under no circumstance try to ride it in.either by coasting or under it's own power. If you get stupid and try to do this let me know so I can make a video for YouTube or Dumbest.er.Funniest Home Videos.
I would not recommend riding up the ramp. That is an accident waiting to happen. I generally just find a ditch or bank to back up to. Get a good ramp with good traction and long enough that the angle isn't so steep.
Earth's core rotates relative to the surface, making its field much stronger, although I'm not sure how that works or if the Moon is responsible.
Actually, Venus is the only one WITHOUT a magnetic field. Mars may have a magnetic field. But Earth, Mercury, Jupiter, Saturn, Uranus and Neptune all have magnetic fields. *below is copied and pasted from source link Scientists believe, although it is not certain, there are two essential ingredients for generating a magnetic field. Those two ingredients are magnetic material currents A bar of iron can be made into a magnet by wrapping it with wires and running a current through the wires. It is believed that a planet, or a star, can generate a magnetic field if it has both of the two ingredients above. It must have enough magnetic material, and it must have currents moving inside the magnetic material. If a planet does not have enough of either of these two ingredients, it will not have a magnetic field. Planets which do not have magnetic fields include Venus (moves very slowly), and Mars (most the iron is on the surface, and not molten).
