Astronomers use the principle of parallax to measure distances to the closer stars. Here, the term parallax is the semi-angle of inclination between two sight-lines to the star, as observed when the Earth is on opposite sides of the Sun in its orbit.
Ernest Rutherford discovered that atoms contain mostly empty space, with his gold foil experiment. Bhor discovered that the electrons are not randomly placed around the nucleu â¦ s.
Other galaxies may contain objects like quasars, the most energetic bodies in the universe, at their core. Astronomers aren't certain of exactly how galaxies formed. After the Big Bang, space was made up almost entirely of hydrogen and helium.