A poor prediction about the possibilities of science was made in 1835 by the prominent French philosopher Auguste Comte. In his Cours de la Philosophie Positive he wrote:

On the subject of stars, all investigations which are not ultimately reducible to simple visual observations are ... necessarily denied to us. While we can conceive of the possibility of determining their shapes, their sizes, and their motions, we shall never be able by any means to study their chemical composition or their mineralogical structure ... Our knowledge concerning their gaseous envelopes is necessarily limited to their existence, size ... and refractive power, we shall not at all be able to determine their chemical composition or even their density... I regard any notion concerning the true mean temperature of the various stars as forever denied to us.

14 years later, the physicist Gustav Kirchhoff discovered that the chemical composition of a gas could be deduced from the spectrum of its light. This method was later extended to astronomical bodies by astronomers using spectrographs attached to telescopes.