The sun, the moon, the stars, they have been all mysterious even in the earliest days of humanity. The earliest civilizations, such as the Sumerians, Ancient Egyptians, and the Indus Valley Civilization, all had a basic understanding of the motions of the moon, the sun, and stars. Some of the people of early civilizations performed methodical observations of the night sky. Celestial events such as eclipses and the motion of planets were also charted and predicted. These early observations are the roots of a later study, called ASTRONOMY. In the past, astronomy has been used to measure time, mark the seasons, and navigate the vast oceans.
Astronomy focuses on the sun, moon, stars, planets, and other objects and phenomena in space. It is considered the oldest of the natural sciences, dating back to antiquity, and is part of every culture’s history and roots.
In this lesson, we are going to talk about:
Astronomy is a scientific study, that belongs to the group of natural sciences, and studies celestial objects and phenomena. It uses physics, mathematics, and chemistry in order to explain their origin and evolution. Celestial objects of interest include the sun, moons, stars, planets, galaxies, and comets.
Professional astronomy has two branches, observational and theoretical.
But, observational astronomy and theoretical astronomy are complementary. Theoretical astronomy seeks to explain observational results, and theoretical results are confirmed by the observations.
Astronomy has four main subfields:
Let's see what is the focus of each subfield of astronomy.
Astrophysics
Astrophysics is the science of physical processes in the cosmos. It uses data gathered by astronomers using telescopes on Earth and in space. Together with the laws and theories of physics interpret the universe around us. Astrophysics builds on astronomy by applying physics and chemistry to the study of celestial objects. Astrophysics can help us in answering so many questions, for example how old is the universe, or what are the stars and what makes them shine.
Astrometry
The branch of astronomy that involves precise measurements of the positions and movements of stars, planets, satellites, comets, and other celestial objects is called astrometry. The information obtained by those measurements provides information on the kinematics and physical origin of the Solar System and our galaxy, the Milky Way.
Astrogeology
The planetary science discipline concerned with the geology of the celestial bodies such as the planets and their moons, asteroids, comets, and meteorites is called Astrogeology. Another term used for Astrogeology is Planetary geology. This science deals with the structure and composition of planets and other bodies in the solar system. Research in this field helps scientists to better understand the evolution of the Earth in comparison with that of the neighbors in the solar system.
Astrobiology
Astrobiology is the study of the origins, evolution, distribution, and future of life in the universe, or we can say that is the study of life in the universe. Astrobiology is formerly known as exobiology. To investigate the possibility of life in other worlds, Astrobiology uses molecular biology, chemistry, geology, biophysics, biochemistry, astronomy, physical cosmology, and other disciplines. Astrobiology is etymologically derived from the Greek words "astron" (constellation, star); "bios" (life); and "logia" (study).
Scientists in the field of astronomy are called astronomers. They observe the stars, planets, moons, comets, and galaxies.
Modern astronomers can be either:
You have probably heard of Nicolaus Copernicus, Galileo Galilei, or Isaac Newton. They are among the most famous astronomers of all time.
Astronomy uses a variety of instruments for observing. They can be broadly divided into two groups. In the first group, belong the instruments used for observing the universe, and in the second group belong instruments that are used to analyze, record, or standardize the data gathered by the observational equipment.
The fundamental instrument of nearly all modern observational astronomy is the telescope.
There are known:
There are known other telescopes, as well as, other astronomical instruments, like the spectrograph, which is also a vital instrument of observational astronomy. The way a prism splits white light into a rainbow, a spectrograph breaks the light from a single material into its component colors. It records this spectrum which allows scientists to analyze the light and discover the properties of the material interacting with it.
