Van Allen Radiation Belts, two zones encircling the earth in which there are relatively large numbers of high-energy (fast-moving) charged particles.
Zenith, the point in the heavens that is directly above the head of the observer. See more »
Zodiac, an imaginary belt in the sky extending some 8 on either side of the ecliptic, the apparent annual path of the sun among the stars. See more »
Zodiacal Light, a faint glow that appears along the zodiac above the western horizon after sunset and above the eastern horizon before sunrise. See more »