Hydrogen is by far the most abundant element in the universe. It makes up about 93 percent of all atoms in the universe and about three-quarters of the total mass of the universe. Hydrogen occurs both within stars and in the interstellar space (the space between stars).
It is an imaginary line from the Earth's north pole to its south pole, passing through the center of the Earth. Imaginary in the sense that it is not marked in any way; howeve â¦ r, Earth rotates around this axis.
eâ¢quaâ¢tor. 1. the great circle on a sphere or heavenly body whose plane is perpendicular to the axis and everywhere equidistant from the poles. 2. the great circle of the earth that is equidistant from the North Pole and South Pole. 3. a circle separating a surface into two congruent parts. 4. celestial equator.