• Question: If the Earth stopped rotating, would gravity change and would the magnetic field close?

    Asked by MichaelM15 to Daniel, Hannah, Maggie, Ry, Scott on 7 Nov 2017.
    • Photo: Maggie Lieu

      Maggie Lieu answered on 7 Nov 2017:

      The gravity on Earth is only determined by the mass of Earth so if we stopped rotating the gravity wouldn’t change, although we would probably feel a horrible jolt! Scientists believe the Earths magnetic field is created by the Earth’s rotation so if it stops, then we would likely lose the magnetic field, our satellites and internet signals would be affected and we’d get an awful dose of radiation :S

    • Photo: Ry Cutter

      Ry Cutter answered on 7 Nov 2017:

      Earth isn’t actually a perfect sphere, due to rotation it bulges a little in the sides. If the rotation stopped the bulges would vanish and Earth would turn into a sphere (very slowly), this would change the gravity around the equator ever so slightly, but we probably wouldn’t feel a noticeable change.
      The Earths core has two parts a liquid outer core and the solid iron core. The rotation of these generates the magnetosphere (the part responsible for the Northern Lights!) Without the rotation there would be nothing to generate the magnetic field. That means the particles stopped by the magnetosphere can travel right down to Earth’s surface 🙁 .
      It would be cool to see what happens the the liquid core part as people think it would crystallize.

      Great Question!

      Ryan

    • Photo: Hannah Middleton

      Hannah Middleton answered on 8 Nov 2017:

      If the Earth stopped rotating, then the gravity wouldn’t change, as the mass is still the same. But we might get quite a different pattern of high and low tides from the ocean, as the tide depends on the position of the Moon above the Earth pulling on the water.

      I think the magnetic field would stop too as it’s dependent on the rotation of the Earth swirling around the fluid material in the molten outer core inside the Earth (which is mostly made of iron). If the Earth stopped immediately, it would probably take a little bit of time for the fluid to stop moving and settle down, so the magnetic field would probably get weaker and weaker first before stopping. But it would probably be the end of life as we know it! The magnetic field protects the Earth from radiation from space, especially from the solar wind.

Comments