El observable universe It is the portion of the cosmos that we can detect and study from Earth or through space instruments. It refers to the space that is within our "observable horizon," which is a kind of limit beyond which we cannot observe objects or events due to the finite speed of light and the expansion of the universe. As science advances, we discover more and more about the universe.
In this article we are going to tell you everything you need to know about the observable universe, its characteristics and what the components of the universe are.
What is the observable universe
In simpler terms, the observable universe is like an expanding bubble that originates from our observation point on Earth. Light travels at a finite speed, and this means that information about objects and events in space can only reach us if it has had enough time to travel to us from its source. As the universe expands, some regions are moving away from us at speeds exceeding the speed of light, meaning we can never receive information from them.
The size of the observable universe is constantly changing as the expansion of the universe continues. Currently, it is estimated that the radius of our observable bubble It is approximately 46 billion light years, meaning we can only detect objects or events that are that distance or closer to us at the current time.
Components of the observable universe
The various types of natural phenomena that make up the structure of the observable universe are better known as astronomical objects or celestial bodies. These entities, visible to the naked eye or through the use of observation devices, they are the fundamental components of the universe.
The vast expanse of the universe is immeasurable, with limitless expanses of empty space intermittently interrupted by massive accumulations of matter and energy. The composition and dynamics of these accumulations determine the formation of various astronomical objects.
Dark matter is an elusive form of matter that remains invisible to observation as it does not emit any electromagnetic radiation. However, It constitutes a significant proportion of the matter in the universe at 26,8%.
Dark energy is a type of energy that is characterized by imprecision, constant density, and the inability to be detected. Its main function is to drive the universe towards expansion. While its current existence remains a matter of cosmological theory, It is believed that up to 70% of the energy in the universe is made up of this particular form of energy.
Galaxies and stars
A galaxy is a collection of stars that orbit around a shared axis, bringing with them various other physical elements, including planets, comets, asteroids, and vast clouds of hydrogen and helium, commonly known as nebulae.
Nebulae are responsible for the typical whitish appearance of galaxies, including the Milky Way, where our solar system resides. The name of this galaxy comes from its resemblance to spilled milk, a stream-like appearance that the ancient Greeks associated with the breast milk of the goddess Hera (known as Juno to the Romans) in their mythological tales.
The stars are distant suns, each with their unique properties and characteristics. These celestial bodies can be considered as large continuous explosions in space that maintain a spherical shape due to their own gravity, which is powerful enough to prevent their elements from being dispersed throughout the universe. The Sun is the most recognizable example of a star.
Planets and satellites
A planet is an opaque, spherical celestial object that orbits another star, typically more massive, along a unique orbital path that is devoid of other planetoids or planets. As each planet forms from pre-existing clouds of gases and cosmic debris, their composition and attributes can be very different from each other. These differences depend largely on the planet's proximity or distance to a star. For example, The atmosphere of the planet Mercury is composed of light and insubstantial gases due to its proximity to the Sun, while Jupiter's atmosphere, located millions of kilometers away, is dense and composed of heavier organic gases such as ethane, methane and ammonia, in addition to hydrogen and helium.
A celestial object that orbits a larger planet and is captured by its gravitational pull is called a natural satellite. These satellites can vary greatly in size, shape and composition, from spherical celestial bodies like our Moon to more irregularly shaped satellites like Deimos, which is one of the largest known satellites of Mars.
The satellites, whether singular like the Earth or plural like Jupiter's 92, They have their own orbits around a planet. However, they also move in conjunction with the planet as it orbits the star. It is essential to keep in mind that satellites are not the same as planetary rings. Planetary rings form from particles, dust and gases that orbit together around a planet, creating a visually uniform disk, as seen on Saturn.
Asteroids and planets
Asteroids are minor, rocky celestial bodies that are too small to be classified as planets, but too large to be classified as meteoroids. They can be found scattered, either alone or in groups known as asteroid fields, which are more or less dense agglomerations. These fragments of matter are variable in size and shape, often having an irregular shape. In the solar system there is an asteroid belt located between the orbits of Mars and Jupiter. Basically, asteroids are nothing more than space rocks with no atmosphere or response to their own gravitational field. Although some asteroids remain stable within a field or belt, others move along more or less erratic orbits around a star, so they can cause catastrophic stellar impacts.
A comet is a celestial body that moves through space, It is usually made up of ice particles, rocks and dust. As it approaches a hot star like the Sun, the comet begins to evaporate, leaving behind a recognizable trail called a tail.
I hope that with this information you can learn more about the observable universe and its characteristics.