Astronomy has made great discoveries in recent years in exploring the origin of the universe.
Nowadays we know much more about stars, galaxies, black holes, new planets, among other celestial bodies observable in the universe.
So, let’s explain what astronomy is and a little more about what’s in the observable universe.
What Is Astronomy And What Does It Do?
Image Source – Urban Samurai
In fact, Astronomy is the natural science that studies phenomena that occur outside the planet earth, such as, for example, cosmic radiation, celestial bodies, comets, stars, planets, galaxies, among others.
As it is a science that studies the stars, it starts to seek comprehensive knowledge about all matter and energy existing in the universe.
In fact, as much as astronomy has advanced very fast in recent years, our conception of the universe is still small in relation to its size.
Origin Of The Universe
As we have already seen, the universe is composed of several elements and is a huge place and for many astronomers, infinite. The Latin word universum means “all in one” or “whole”.
Therefore, there are several theories about the origin of the universe, but the model supported and accepted by scientists is the famous “Big Bang Theory”.
According to the theory, 14 billion years ago, it hears a big explosion of a single and small particle, called primordial atom.
Big Bang – Origin of the Universe
In which it caused a cosmic cataclysm, thus generating the entire origin of the observable universe. This theory also reinforces that the Universe is in continuous expansion.
Some Elements Of The Universe
The celestial bodies of the universe are many, but we have separated the main ones briefly.
Stars | They have their own light and heat and have a spherical plasma shape. Our sun, for example, is a star.
Planets | They are solid and rounded and have no heat of their own. However, each planet has its own gravity. Planets orbit around the sun
Galaxies | It is the set of stars, planets and gases. Our planet Earth is located in the Milky Way galaxy. There are approximately 100 billion galaxies in the universe.
Satellites | They are solid celestial bodies that orbit the planets. There may be natural satellites, such as the Moon, or natural satellites such as Sputnik.
Comets | They are celestial bodies with little mass and irregular orbit. A very famous one is Comet Halley, visible in many places in the world with the naked eye and telescope.
Some facts about our universe
1. The Sun we see is from the past
Sunlight takes just over eight minutes to reach us. This is because the speed of light is finite (approximately 300,000 kilometers per second) and the distance between the Earth and the Sun is about 150 million kilometers. So when we look at this star, the image we see is from the past! If she disappeared for some unexpected reason, we wouldn’t know until eight minutes and 18 seconds later.
2. We are traveling over 100,000 km/h
Did you know that the Earth orbits the Sun moving at speeds close to 107,000 km/h? This speed is variable, since the Earth’s orbit is not perfectly spherical but elliptical.
This is why the Earth’s speed changes: when we are closer to the Sun, its gravity becomes more intense, pulling the Earth with a greater force. The position where the Earth is closest to the Sun is called perihelion, while the position further away is called aphelion.
As if that wasn’t enough, in addition to rotating around the Sun with such speed, the Earth still rotates around its own axis, with a speed that can reach more than 1500 km / h. This is according to its position in relation to the equator: the closer to it, the greater the rotation speed.
The reason we don’t feel any of these rotational motions is related to centripetal acceleration. Centripetal acceleration allows us to feel that we are rotating, however, in the case of the Earth, as the radii of the rotation and translation movements are very large, the centripetal acceleration produced by them is very small compared to the acceleration of gravity.
3. Big Balls of Gas
Only four planets in the Solar System are telluric, that is, they have rocky soil. The rocky planets in the Solar System are Mercury, Venus, Earth and Mars. The other planets in the system are formed exclusively by a large heap of gases trapped by a large gravitational interaction.
4. The Galactic Year
The galactic year is the time required for the Sun to complete one revolution around the center of our galaxy, a time of approximately 250 million years. The Milky Way is a spiral galaxy, and the Solar System is in one of its arms.
The Solar System orbits the center of our galaxy, as it is bound by the gravitational pull exerted by the Sun. It is estimated that the entire Solar System performs this orbital movement at a speed of approximately 828 thousand kilometers per hour. However, this speed is very small compared to our galaxy, which is more than 100,000 light years in diameter.
5. Black holes
Contrary to what many think, black holes were not discovered by Albert Einstein, but were proposed by Karl Schwarzschild. The existence of these structures was predicted by Schwarzschild as possible solutions to Einstein’s equations of general relativity.