GEOLOGY

Detailed explanation-1: -In the ionosphere, the ions of the solar wind collide with atoms of oxygen and nitrogen from Earth’s atmosphere. The energy released during these collisions causes a colorful glowing halo around the poles-an aurora.

Detailed explanation-2: -Most of the auroral features are greenish-yellow, but sometimes the tall rays will turn red at their tops and along their lower edges. On rare occasions, sunlight will hit the top part of the auroral rays to create a faint blue color.

Detailed explanation-3: -The auroral lights’ colors are determined by the spectra of gases in the Earth’s atmosphere, and the height at which the most collisions take place. Incoming particles tend to collide with different gases at different heights.

Detailed explanation-4: -The short answer to how the aurora happens is that energetic electrically charged particles (mostly electrons) accelerate along the magnetic field lines into the upper atmosphere, where they collide with gas atoms, causing the atoms to give off light.

Detailed explanation-5: -The most abundant gas is molecular nitrogen, and it radiates promptly in deep blue and red colors. Mixing these together gives purple. The bottom edge of a green auroral curtain gets this purple color when auroral elec-trons are accelerated to very high energy (Figures 7-8).