Space. Solar System. Discovery and exploration Andreas Cellarius's illustration of the Copernican system, from the Harmonia Macrocosmica (1660) For many thousands of years, humanity, with a few notable exceptions, did not recognize the existence of the Solar System.
People believed Earth to be stationary at the centre of the universe and categorically different from the divine or ethereal objects that moved through the sky. Nebula. Portion of the Carina nebula A nebula (from Latin: "cloud";[1] pl. nebulae or nebulæ, with ligature, or nebulas) is an interstellar cloud of dust, hydrogen, helium and other ionized gases.
Originally, nebula was a name for any diffuse astronomical object, including galaxies beyond the Milky Way. The Andromeda Galaxy, for instance, was referred to as the Andromeda Nebula (and spiral galaxies in general as "spiral nebulae") before the true nature of galaxies was confirmed in the early 20th century by Vesto Slipher, Edwin Hubble and others. The Scale of the Universe 2.