Do you know what exactly a galaxy is? Do you know what a black hole is? And the difference between an asteroid and a meteorite? Scroll through the next lines and see some definitions and curiosities about the best-known objects, and others have not so well known, from the universe.
Do you know that Galaxies are systems made up of black holes, nebulae, stars, planets, moons, comets and other types of events and cosmic matter. There are three main types of galaxies: elliptical, spiral and irregular. Called the Milky Way, the address of the solar system is a spiral-type galaxy. It has around 200 billion stars.
Do you know that Constellations are sets of stars next to each other such as seen from Earth. They are connected by imaginary lines, forming different figures. The constellation of Orion is partly formed by 3 aligned stars called As Três Marias. For ancient Greeks, they represented the Orion Belt.
Do you know that Stars are celestial bodies that produce their own light. They are mainly composed of hydrogen and helium. They vary widely in size and in many, many cases have structures like planets in their orbit. There are several types of stars: white dwarfs, red dwarfs, neutron stars …
Do you know that White dwarf is the final phase of a star, after it has shed its outer layers, leaving only the core. They are small bodies, with dense and hot matter, besides intense shine.
Do you know that Neutron stars are super-compact, ultra-massive bodies that spin very fast and have extremely high gravity. They are formed when stars with a mass eight times greater than that of the Sun deplete their nuclear energy.
Do you know that Black holes are celestial bodies with gigantic mass and gravitational field, which attract everything around. Not even light can escape its Do you know that gravity. It appears when a star with a mass at least 25 times that of the Sun consumes all its fuel and implodes. The nucleus collapses (let’s say it “collapses on itself”) and after a certain moment the star starts to behave as a kind of cosmic drain, sucking all the matter around.
Do you know that Quasars (quasar is short for “almost stellar”) are giant black holes in the center of galaxies. They are strong emitters of light and radio waves. This type of celestial body spins extremely fast. Astronomers believe they are some of the oldest and most distant objects in the universe.
Do you know that Nebulae are gigantic clouds of gas and dust, in which stars are born. It got its name because they look like clouds. The best known nebulae are Water, Orion, Cat’s Eye and Tarantula.
Do you know that Planets are mostly spherical bodies that orbit stars, glow when reflecting light and are larger than asteroids. They can be rocky or gaseous. The largest planet in the solar system is the gas giant Jupiter.
Do you know that Moons are the natural satellites of the planets. They are generally spherical in shape and are almost entirely rocky. The largest moon in the solar system is Ganymede, one of more than 70 satellites orbiting Jupiter.
Do you know that Comets are immense rocks of ice and other elements – ammonia, carbon dioxide, etc. – that roam the solar system. It is said to be what remains of the formation of gaseous planets like Saturn and Jupiter. The comet’s tail is generated by the sun’s heat. The closer it is to the star, the bigger its tail.
Do you know that Asteroids are rocky bodies with a defined orbit around the Sun. They are the smallest bodies in the solar system, measuring from a few meters to tens of kilometers. They are irregularly shaped and in some cases are orbited by other asteroids.
Do you know that Meteorites are fragments of asteroids, comets and other celestial bodies that fall to Earth. They can vary immensely in size, and can be as thick as a grain of sand to the size of a building. The largest meteorite ever found is no less than 59 tons.
Do you know that Dark matter is a kind of substance different from the “we see” matter, which emits electromagnetic radiation in the form of radio waves, x-rays, etc. We know of its existence through the gravitational effects on celestial bodies. Along with dark energy, of which we also know very little, it forms the bulk of the universe