Video: What is a planet? The controversy continues
2024 Author: Henry Conors | [email protected]. Last modified: 2024-02-12 02:47
If you know what a planet is, then you know more than astronomers. Because they are not sure about the definition of this term. For example, some consider Pluto a planet, others do not.
Initially they called Mars, Venus, Jupiter, Saturn, Mercury. By the way, the names of the planets came to us from Greek and Roman mythology. The earth was special for the ancients, different from other celestial objects. The Moon and the Sun were also ranked among the "wandering bodies" of a slightly different nature. Have you ever wondered why we have one day off every seven days? This is not reflected in Russian. But in French, Italian, for example, there is a clear connection between this “magnificent seven” and the days of the week: Monday - the Moon, Tuesday - Mars, Wednesday - Mercury, Thursday - Jupiter, Friday - Venus, Saturday - Saturn, Sunday - the Sun.
Uranus was discovered in the 18th century. Then, thanks to the research of Le Verrier and Adams, Neptune (in the 19th century). In 1930, the world learned about the existence of Pluto. This discovery was made by Clyde Tombaugh. Pluto is still called the ninth planet. Is it so? In order to answer this question, you need to figure out what a planet is?
This concept itself has been formed historically. We see five planets in the sky with the naked eye. And everything would be much more complicated if the asteroids were brighter. Astronomers have agreed to call an object orbiting a star a planet, plus it must be large enough to become a sphere due to gravity. Many comets and asteroids have very strange shapes.
There was no exact definition of "what is a planet". But still, such a name was assigned to Pluto. In fact, this is a very strange object, and it is very different from the rest of the large planets. Its orbit is somewhat more elongated. As it turned out, Pluto is very small. Much less than astronomers previously thought. All the planets of the solar system are located "by growth": 4 earth groups at the beginning, then the giant planets. Pluto clearly doesn't fit in here.
Then they discovered Pluto's satellite - Charon, which is almost the same in size. This is also somewhat atypical: all planets have a much smaller satellite.
Kuiper (American astronomer) suggested that there is an asteroid belt beyond Neptune. This was another blow to the "status" of Pluto. There really is such a belt! It is currently known as the Kuiper belt. The bodies in it are somewhat different from asteroids. But they are very similar to Pluto, only smaller in size. Now it has become clear to everyone that Pluto is one of the large objects of the Kuiper belt. But for now, it retains its original name. Scientists are mostly humanconservative, so we decided to leave everything as it is for now.
And yet, what is a planet? Soon this question will become very relevant. Because it is known that planets of other stars are already being discovered.
The main parameter is mass. Smaller objects are asteroids, more massive are stars. Everything is clear with the stars. They must have a high temperature for thermonuclear processes to occur. The planet in its orbit should be one, if there are many objects (“belt”), then these are asteroids.
Recommended:
The nastiest animals on the planet: description, rating
According to various estimates of scientists, about two million varieties of living beings live on planet Earth. Many of them are cute to most people, but there are those that look really scary. In this article, we will look at the rating of the ugliest animals and talk about each of them
The oldest person on the planet: how to repeat the record?
Officially register the birth of a new inhabitant of the planet began not so long ago. It hasn't even been 100 years since the invention of the birth certificate. In this regard, it is not so easy to determine who lived the longest. Let's try to figure it out
Developed countries of the planet
Having gone through all the stages from feudalism to a market economy, the states of the planet Earth were divided into categories, the leading of which is a set called "Developed countries"
Ecological problems of the planet. Global environmental problems of the planet: examples
Every modern inhabitant of the Earth knows very well that the environmental problems of the planet are a real scourge of the 21st century. Also, many think about the issue of preserving and restoring the environment. After all, otherwise future generations will get only a lifeless surface
The population of Dimitrovgrad continues to decrease
A small town in the Ulyanovsk region did not escape the fate of renaming, according to the Soviet tradition. In 1972, Melekessians became Dmitrovgradians. The population of Dmitrovgrad has been constantly decreasing in recent decades, which is associated with not the best state of the city's economy