This animation demonstrates very simply how different elements at different heights, let off energy that we see as different colors.
Click on image for full size

Axis Tilt

Axis tilt occurs when a planet’s rotational axis is tilted relative to the plane of its revolution around a larger object. Put simply, that means that the “top” of the planet, as defined by its rotation, is tilted. If a planet is titled in our solar system that means that sometimes the top of the planet faces the Sun and sometimes it faces away as it revolves around the Sun.

The Earth is tilted by 23.5 degrees, which means that sometimes the northern hemisphere is tilted toward the Sun and sometimes it is tilted away from the Sun. This tilt of a planet is what gives us seasons.

Not all the planets have the same amount of tilt. Jupiter, for instance, has almost no tilt (3 degrees), while Venus has almost 180 degrees of tilt, which means that it’s spinning upside-down (at least relative to our definition of up). Uranus has a tilt of almost 90 degrees, which means that this planet is spinning on its side!

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