Why does Earth, the uh.....uh.....the third planet in our solar system, have a magnetic molten core?

Question

vs. Mars, for example, which doesn't? Most other planets don't neither to my knowledge. Why did we get lava and everything, man?

Answer 1

Good question. Like Earth, Mars has an iron core, and used to have a magnetic field. Whether some or all of Mars's core is liquid is a question awaiting further examination. Earth's magnetic field appears to be due to convection currents in the molten outer core, but there's a lot we don't understand about what sustains the process. A further mystery is why Mercury has a (weak) magnetic field.

Answer 2

The magnetic field is the result of currents in the liquid iron outer core, which themselves are caused by the Coriolis effect of the earth's rotation. In dynamo theory, currents in an electrically conductive liquid, such as iron, can retain a magnetic field. The core of Mars is solidified, and Venus has almost no spin. Jupiter's magnetic field is extremely strong, but this is due to liquid metallic hydrogen rather than iron.



Lava has nothing to do with a magnetic field. Mars once had active volcanos, and Venus still does.

Answer 3

Uh.

It is because of Earth's mass and volume.

Our mantle and core hasn't had time and is under so much pressure, it is rock, like the rest of the World but it acts like it was molten.

The heavier elements like metals and nuclear materials sink to the centre and spin separately to create the dynamo effect that gives us our Magnetic field.

Mars lacked the mass and therefore the same internal heat from fission and pressure to maintain its magnetic core for too long, it cooled down. it must have had a mantle though, judging by its massive extinct volcanoes.

Venus is just slightly smaller than Earth and its core takes up about 1/2 of its interior, it shows no techtonics but has shield volcanoes.

Io, a moon of Jupiter bucks the whole trend, but it has a highly eccentric orbit and gets pulled wither by gravity making it the most volcanically active body in the solar system.

Answer 4

Mars *had* one, at one time - but, without fissionable maerial keeping it heated, it has frozen - which allowed the magnetic field to die also. Venus has a hot core, it's believed, but it's unclear if it's solid or liquid. Venus' core is also larger than ours, based on orbital mechanics of spacecraft, it's thought that it's metal core is 3000km wide, while it's mantle is about 3000km deep.

Earth has a solid inner core, surrounded by a liquid outer core; the inner core is still solidifying - growing at an estimated millimeter or so each year. Part of the heat in our core is from radioactive decay; that has helped drive the convection currents in the outer core, maintaining Earth's magnetic field. And, the radiative heat rises into the mantle, giving us tectonics, volcanoes, and lava.

And Hawaii, too!

Answer 5

As best I can tell, they had to give Earth some good stuff, and some bad stuff. So, like they gave us fresh water lakes, rivers, streams and moderate sunlight. Then they tossed in some of the crap like Lava, Tsunamis, Asteroid Crashes, bad diseases, and other stuff like that. In the end, it all sort of balances out, don't cha know?

Answer 6

venus has a molten core denser then ours....

Answer 7

Uh Uh Uh :)

Answer 8

Uh uh...