What is astronomy?

We explain what astronomy is and what is the history of this science. In addition, its branches of study and its difference with astrology.

1. What is astronomy?

Astronomy is known to science that is dedicated to the study of the celestial bodies that populate the cosmos : stars , planets , satellites, comets , meteorites , galaxies and all interstellar matter, as well as their interactions and movements.

It is an extremely ancient science, given that the sky and its mysteries constituted one of the first unknowns that the human being formulated, giving them in many cases mythological or religious answers. It is also one of the few sciences that currently allows the participation of its fans .

In addition, astronomy has not only existed as an independent science, but has accompanied other areas of knowledge and other disciplines, such as navigation – especially in the absence of maps and compasses – and more recently physics, for whose understanding of fundamental laws of the universe the observation of the behavior of the cosmos turns out to be of enormous and unequaled value.

Thanks to astronomy, humanity has achieved some of its greatest scientific and technical milestones of recent times, such as interspatial travel, the positioning of the Earth within the galaxy, or the detailed observation of the atmospheres and surfaces of the planets of the System Solar , when not systems many light years from our planet.

2. Astronomy history

Astronomy is one of the oldest sciences of the human being , since since ancient times the stars and bodies of the celestial vault have captured their attention and curiosity. Great scholars of this field were the philosophers of antiquity such as Aristotle, Tales of Miletus, Anaxagoras, Aristarchus of Samos or Hipparchus of Nicea, post -centralist scientists such as Nicholas Copernicus, Tycho Brahe, Johannes Kepler, Galileo Galilei and Edmund Halley, or contemporary specialists like Stephen Hawkins.

The ancients thoroughly studied the sky, the Moon and the Sun, so much so that the ancient Greeks already knew about the roundness of the Earth , but assumed that the stars revolved around the planet, and not vice versa. This would remain until the end of the European Middle Ages, when the Scientific Revolution questioned many of the universal foundations that religion held as sacred.

Subsequently, already in the twentieth century, the new advanced technologies available to mankind allowed a greater understanding of light and therefore of telescopic observation technologies, bringing with it new understandings of the universe and the elements that compose it.

3. Branches of astronomy

Astronomy includes the following branches or subfields:

• Astrophysics . Fruit of the application of physics to astronomy, to explain celestial properties and phenomena, formulating laws, measuring magnitudes and expressing results mathematically through formulas.
• Astrogeology . Known as exogeology or planetary geology, it is the application of the knowledge obtained during excavations and telluric observations on planet Earth, to other celestial bodies whose composition can be known from afar or, even, as is the case with the moon and mars, through the sending of rock sample collection probes.
• Astronautics . From watching the stars, the man began to dream of visiting them. Astronautics is precisely the branch of science that seeks to make that dream possible.
• Celestial mechanics . Fruit of the collaboration between classical or Newtonian mechanics and astronomy, this discipline focuses on the movement of celestial bodies, due to the gravitational effects that other bodies of greater mass generate on them.
• Planetology . Also called planetary sciences, it focuses on the accumulated knowledge of known planets and for knowing, that is, those that make up our solar system and those that are far from it. This ranges from objects the size of a meteor to huge gas giants.
• Astronomy X – rays . Together with other astronomical branches specializing in types of radiation or light (electromagnetic radiation), this branch constitutes a specialized approach in measuring X-rays from outer space, and the conclusions that can be drawn from the universe from them.
• Astrometry . It is the branch in charge of measuring the position and astronomical movements, that is, in some way mapping the observable universe. It is perhaps the oldest branch of all.

4. Difference between astronomy and astrology

The difference between these two disciplines is fundamental. When we talk about astronomy, we refer to a science that logically uses the scientific method to carry out its measurements and checks, which can be refuted and based on analysable experiments and theories with mathematical support.

Astrology, on the other hand, is an “occult science” or  pseudoscience , that is, an interpretative doctrine of reality that has no scientific basis, nor responds to other fields of verifiable factual knowledge, but is sustained on the basis of its own and exclusive rules of the game. If astronomy is the scientific understanding of the cosmos, astrology is the explanation of terrestrial phenomena through figures arbitrarily drawn on the stars.