Humanity has long looked up to the sky, seeking to name and organize them in the universe around us. Although constellation movements – patterns embedded in the night sky – are easy to follow, other cosmic events such as solar eclipses, lunar eclipses and planetary movements have also been observed, sorted and predicted.
What is astronomy?
Astronomy is the study of the Sun, Moon, planets, comets, gas, dust, galaxies, stars, and other objects beyond Earth.
According to NASA’s definition, “Astronomy is the science that studies the stars, planets and space.”
Astronomy and astrology have a lot to do with history, but astrology is not a science and it is said to have nothing to do with astronomy.
Historically, astronomy has focused on observing objects in the sky. It is a close brother of Astrophysics. In short, astrophysics studies the physics of astronomy and focuses on the behavior, properties, and motion of objects in the universe. However, modern astronomy includes many elements of the motion and properties of these objects, and the two concepts are often used interchangeably.
Modern astronomers work on two branches: theoretical and observational.
- Observational astronomy focuses on the direct study of stars, planets, galaxies, etc.
- Theoretical astronomy focuses on modeling and analyzing the evolution of systems.
Unlike other scientific fields, astronomers cannot observe a system from birth to death. The lifetimes of stars and galaxies range from millions of years to billions of years, so astronomers must rely on images of objects at various stages of evolution to determine how they form, develop and end. As such, theoretical and observational astronomy tend to mix: theoretical astronomers use the actual information gathered to create simulations, while observational astronomers use observations to validate models – or suggest requirements for refining them. .
Astronomy is divided into several subfields, allowing scientists to specialize in specific phenomena and objects.
Planetary astronomy: focuses on the development, evolution and end of planets, while solar astronomers spend time analyzing a single star – our Sun. Stellar astronomers look to stars, including black holes, nebulae, white dwarfs, and supernovae that exist when a star dies.
Galactic astronomy specializes in the study of galaxies, the Milky Way, while extragalactic astronomers look beyond the galaxy to determine how these star clusters form, change and die.
Cosmologists focuses on the universe in all its glory, from the aftermath of the Big Bang to its current evolution, until its end.
Astronomy is often (not always) very specific to observables, while cosmology is often concerned with large-scale properties of the universe, and mysterious, unseen and sometimes purely theoretical things like: string theory, dark matter and dark energy, and the concept of the multiverse.
Astronomical observers rely on different wavelengths of the electromagnetic spectrum (from radio waves to visible light and even X-rays or gamma rays) to study a wide range of objects in the universe. Early telescopes focused on the simple optical study of things visible to the naked eye, and many telescopes continue that mission today.
But when light waves carry stronger or weaker energy, travel faster or slower, different types of telescopes are needed to study at different wavelengths. More energetic radiation, with shorter wavelengths, occurs in the ultraviolet, X-ray and gamma-ray wavelengths, while lower energy carrier objects have longer wavelength radiation. wave in infrared and radio.
Star measurement technique, one of the oldest branches of astronomy, is the measurement of the Sun, Moon and planets. Precise calculations of these movements allow astronomers in other fields to build models of the formation and evolution of planets and stars, and to predict events such as solar eclipses, lunar eclipses, meteor showers and the appearance of comets.
The first astronomers Pay attention to the patterns in the sky and try to arrange them to make it easier to track and predict their movements. Known as constellations, these patterns once helped people measure the seasons. The movements of stars and other celestial bodies are tracked all over the world, most often in China, Egypt, Greece, Mesopotamia, Central America and India.
The image of an astronomer is a lonely soul with a telescope all night. In fact, the hardest part of astronomy today is done with observatories by computer-controlled telescopes – on the ground and in space – and with astronomers. Literature studies data and computer-generated images .
Since the advent of photography, and more specifically digital photography, astronomers have provided amazing images of space, not only in scientific works but also in captivating the public. .
Astronomers and space programs also contribute to the study of our planet, as missions mostly consist of looking outward (or traveling to the Moon and beyond) and taking amazing photos of Earth from above. ‘space.
Théo Hien Phan – VLTV – Space