The aurorae are the bright, dancing light display seen in the northern and southern latitude on Earth. The aurorae are caused by ionized particles from the solar wind being captured by magnetic field lines from the Earth's magnetosphere The particles spiral around the field lines and slam into the atmosphere, creating plasma, which we see as the aurorae. Depending on the atoms involved, different colors can be seen.
If there were not a magnetosphere around the Earth, the Earth would be a barren planet. The magnetosphere not only creates the beautiful aurorae, but also prevents the solar wind from stripping away the outer layers of the atmosphere as it has done to Mars and completely strips away the atmosphere or Mercury.
Why do we have a magnetosphere and Mars does not? The simple answer is the Earth's core. The Earth's core is a molten ball of iron and nickel, two ferromagnetic metals. The molten core then rotates, which creates a magnetic field around the core, which in turn encompasses the entire planet. Mars, however, has a core that solidified over 4 billion years ago and over time, the solar wind was able to strip the outer layers of Mars' atmosphere away, leaving behind the planet we see today. Our core stays molten from intense heat from the outer layers of the Earth pushing on the core as well as radioactivity in the core.
Other planets also demonstrate aurorae, especially the Jovian planets which all have molten iron/nickel cores.
Earth has two types of aurorae, the Aurora Borealis and the Aurora Australis. The names only refer to the location of the aurora. The Aurora Borealis are seen in the northern latitudes in the northern hemisphere and the Aurora Australis are seen at the southern latitudes in the southern hemisphere.
Here is a link to a page that shows the forecast for the Aurora Borealis. Maybe you may be able to see aurora in your neighborhood!
No comments:
Post a Comment