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.
Earth's Rotation. Earth's Rotation and the Apparent Daily Motion of the Sky . The earth rotates about an imaginary line that passes through the North and South Poles of the planet. This line is called the axis of rotation. Earth rotates about this axis once each day (approximately 24 hours). Although you most likely already knew that fact, there is a slight complication most people are not aware of.