Aerospace comprises the atmosphere of Earth and surrounding space. Typically the term is used to refer to the industry that researches, designs, manufactures, operates, and maintains vehicles moving through air and space. Aerospace is a very diverse field, with a multitude of commercial, industrial and military applications.
“Aerospace” is not the same as “airspace”, which is a term used to describe the physical air space directly above a location on the ground. “Aerospace” can be understood as the combination of aeronautics and astronautics.
Astronomy is a natural science that deals with the study of celestial objects (such as moons, planets, stars, nebulae, and galaxies); the physics, chemistry, and evolution of such objects; and phenomena that originate outside the atmosphere of Earth (such as supernovae, gamma ray bursts, and cosmic background radiation). A related but distinct subject, cosmology, is concerned with studying the universe as a whole.
Astronomy is one of the oldest sciences. Prehistoric cultures left behind astronomical artifacts such as the Egyptian monuments and Nubian monuments, and early civilizations such as the Babylonians, Greeks, Chinese, Indians, Iranians and Maya performed methodical observations of the night sky. However, the invention of the telescope was required before astronomy was able to develop into a modern science. Historically, astronomy has included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars, but professional astronomy is nowadays often considered to be synonymous with astrophysics.