The sky has always attracted people, so distant and mysterious. For some time now, we have been successfully comprehending the mysteries of space, learning more and more new information about stars, planets and other objects of the Universe. With today's development of astronomy and cosmology, the difference between a planet and a star is basic knowledge.
Planet is a rotating astronomical object with a spherical shape, which has an average mass by cosmic standards. A star is a celestial body, the main feature of which is the thermonuclear chemical reactions occurring inside it. Thus, stars glow due to these reactions. Naturally, all stars “during their lifetime,” that is, while reactions are taking place, are much hotter than the planets. Planets do not emit light; they can only reflect it. Typically, stars are much larger in mass than planets, although this depends on the stage of the star's life. This usually means a larger diameter (size). A planet is distinguished from a star by the fact that it is not a field for thermonuclear reactions (which occur massively and naturally), since planets do not have sufficient mass for this. With a mass of thirteen Jupiter masses, the planet turns into a star. Both objects rotate around their own axis. At the same time, the planet also rotates relative to its star. However, this fact is currently disputed by scientists, as objects very similar to planets that do not orbit stars have been seen.
Surface stars not solid, since a star is a mixture of gases and dust. As we know, planets in this regard are not so homogeneous: gas planets are known, as well as planets with a solid surface, like our Earth. Planets have a magnetosphere, that is, a “magnetic atmosphere” created by the planet’s own magnetic moment. A weak magnetic field is not able to retain the planet's atmosphere, although such cases are rare. Stars have no atmosphere. And the chemical composition of the star is dominated by “light elements” - with a small atomic number (for example, carbon, helium).
Conclusions website
- The star is supported by thermonuclear reactions taking place in it.
- The planet is much lighter than the star and also smaller in diameter.
- Planets and stars have different chemical compositions and temperatures—planets are much colder.
- Stars have no atmosphere
- Stars emit light, planets cannot do this.
- Planets revolve around stars.
It turns out that there are so many different bodies in the Galaxy and they are all divided into types and classes. For example, more than once you hear that on such and such a planet or star... and so on. What is the difference between a star and a planet?
The difference between them is quite large, although not noticeable at first glance. To make it more clear, imagine our Sun and Earth. The sun is a real star. But the Earth is a planet. And now we will consider all the differences in relation to them.
The very first and most important thing- the star emits light. On a skyscraper it looks like flickering. But the planet only reflects light. They themselves are dark bodies and if light does not fall on them, then it will be impossible to see them.
Secondly, stars have much higher temperatures than planets. On the surface of stars, the temperature ranges from 2,000 to 40,000 degrees, not to mention the center, where it can possibly reach millions of degrees. This is not yet known for sure, since modern science does not know of a single device that could withstand such temperatures.
Third, the mass of the star is much higher than the mass of the planets. As a rule, all stars are very massive bodies. But the planets are much smaller.
Fourthly, the planets move relative to the stars. Absolutely the same as our Earth around the sun. And the stars remain motionless relative to the planets. In other words, planets move around their stars and always along an elliptical path. This is noticeable if you observe the starry sky for several nights in a row. This also explains the fact that, unlike stars, planets “show” different phases just like the moon.
Fifthly According to its chemical composition, the planet contains both solid and light elements. But the star is mostly just light.
At sixth, planets often have from one to several satellites at once, but stars never have them. Although, of course, the absence of a satellite does not mean that it is not a planet.
And seventhly, thermonuclear or nuclear reactions necessarily occur on all stars. Such reactions are not observed on planets. In exceptional cases, only nuclear and very, very weak, and then only on nuclear planets.
Astronomy is a very ancient science that studies cosmic bodies, stars, planets, etc. Although astronomers have been studying space for a long time, it remains inaccessible, since the distances to any planet can range from hundreds of thousands of kilometers. In science there is such a unit of measurement as light years. Enormous distances do not provide the opportunity for a full study of a particular object.
Many people love to watch the starry sky at night, where countless stars twinkle. The Milky Way is clearly visible; if you look closely, you can find Ursa Major and Ursa Minor; Venus is the first to light up in the starry sky. However, many do not even know that in the shining starry sky not only stars are visible, but also planets, and their differences are enormous.
Description of the planets
Planets are bodies in space with a solid consistency, their shape is similar to balls, that is, they have a round or slightly oval shape. A characteristic feature of planets is that they are constantly in motion, “flying” around the stars that are located next to them. An example of this is that our planet Earth moves around the Sun, i.e. flies around it in one year. During its movement, the Earth either approaches the Sun or moves away a little. Therefore, during one completed revolution, the seasons of the year change on the planet. The Earth, like other planets, moves along a certain route, which has a name such as orbit. If there are other objects in orbit besides the planet, then they are called asteroids.
Planets, by themselves, never glow; they simply, like a mirror, reflect the light that their stars give them.
More than five billion years ago, the Solar System and all the planets that are part of this system appeared. The story of their origin is as follows: a huge cloud consisting of gas and dust arose in outer space. In the center of it, compaction occurred and, due to thermal nuclear reactions, a star was lit, which later became known as the Sun. In the remaining cloudy area, they began to unite into dense objects, and gradually, step by step, turned into planets. The temperature emanating from the Sun was so high that light gases rapidly evaporated and petrified very quickly on top of the planets.
Stars - definition
A star is a body located in space where thermonuclear reactions occur. They are huge bright and luminous balls. As a result of gravitational compression, they are formed from a gas and dust environment. The temperature inside stars is very high, measured in millions of Kelvin (Kelvin is a unit of measurement for the temperature of stars). Very often, scientists call stars the main bodies that can be found in the Universe. This is explained by the fact that they contain the bulk of the luminous substance in nature.
Any star is a huge ball filled with hot gases.
The composition of these gases is:
- Hydrogen – 90%.
- Helium – slightly less than 10%.
- The remaining part consists of admixtures of other gases.
At the moment when hydrogen turns into helium, a huge amount of energy is released, the temperature in the central part of the object is 6,000,000 0 C. It is this energy that gives stars the ability to emit light.
The difference between planets and stars
They differ very much from each other, although initially no difference is visible. Looking into the night sky, you can notice flickering here and there. This is their first difference.
- The star glows very brightly, and we can see it from anywhere on the globe. The planets only reflect the light they receive. Externally, planets appear as dark celestial objects and, without the glow of a neighboring star, it would be impossible to see the planet.
- Stars have a huge above-zero temperature, which planets cannot boast of. The temperature on top of any star can reach up to 40000 degrees, and in its central part it can reach millions of degrees. Modern science has not produced such a device with which it would be possible to measure such high temperatures.
- The weight of stars significantly exceeds the weight of planets. The star has a massive size, and the planets seem to be just crumbs.
- The stars are always motionless, which cannot be said about the planets. They move around the axis of the stars. An example of this: The Earth moves around the Sun, which is motionless in relation to it.
- The planets are composed of solid and light elements containing gas. Stars are filled with light substances.
- All planets have one or several satellites at once (for example: The moon is a satellite of the Earth). Stars do not have the luxury of their own satellite. But there are also some nuances - the missing satellite does not mean that it is not a planet. This requires a long study.
- Nuclear reactions necessarily occur on all stars. There are simply no such features on planets.
So, planets differ from stars in many ways, but much has not yet been studied.
Based on all the materials studied, the main difference between a star is its ability to glow. Venus looks bright and impressive in the sky, reflecting the light coming from the Sun.
If you look into the sky and see a flickering object, you can be sure that it is a star. If an object glows with an even, cold light, it is a planet.
The planet, compared to the star, has its own orbit, and it will not be able to leave it. An orbit is a kind of path that helps a planet move around its star.
The sizes of planets and stars differ enormously from each other. The stars are simply gigantic in size, and the planets seem like small grains of sand in comparison.
If you think about it and imagine what size stars can reach, and take into account that there are countless galaxies in the universe, then you can understand, although it is difficult, what infinity is.
Video about comparing the sizes of stars and planets:
A planet (Greek πλανήτης, alternative form of ancient Greek πλάνης - “”) is a celestial body that revolves around a star (or the remains of a star) in its own orbit.
A star is a massive ball of gas, which is characterized by light radiation and flows in its depths. Stars are held together by the forces of their own gravity, as well as internal pressure.
Let’s make a reservation right away: only the planets of our solar system can be detected with the naked eye.
Planet, star. Differences
Both the planet and the star are characterized by a glow, by which, in fact, they can be seen from Earth. However, a star is a self-luminous object. While the planet glows due to light reflected from the stars. Therefore, the radiation of the planets is several times weaker than the stellar radiation. This is especially noticeable on a frosty night or. The shine of stars is much more intense (especially those closer to the horizon). The glow of the planets is muted or even indistinct.
Venus and Jupiter, by the way, are an exception to the rule. They can be easily recognized by their characteristic glow, which is much brighter than some distant stars. In addition, pay attention to the shade of the radiation. Venus is distinguished by its cool bluish-white glow. Mars is reddish, Saturn is yellow, and Jupiter is yellow with an admixture of white.
Another distinctive feature is the nature of the light radiation. Stars are more likely to flicker due to air vibrations. Even in the lenses of powerful telescopes, stars are represented by blinking dots. The planets, in turn, shine evenly, albeit dimmer.
The most effective method to recognize a celestial body is to observe the object. It is recommended to observe the sky for several days. You can even graphically record the location of the main bodies and compare the results day by day. The point is that the stars are stationary in relation to each other. The only thing that will change for them is the time of their appearance in the sky. Planets, on the contrary, are characterized by inconstancy. They move along unimaginable trajectories relative to the stars, sometimes changing their route to the opposite.
Space tricks
There are certain nuances that you need to know when observing the sky. Venus, for example, invariably appears in the East, just before sunrise. Visually, it resembles a bright spot during this period. If you look in the right direction at night, you can see Jupiter.
It would be a good idea to familiarize yourself with the astrological calendar. With its help, you can find out in advance which planets will be in sight at certain periods of time.
The main difference between stars and planets is that stars have higher temperatures compared to planets. Stars undergo nuclear reactions - they burn hydrogen in their cores, releasing huge amounts of energy. Stars must have a mass at least 75 times that of Jupiter, the largest planet in the solar system. Because they radiate energy, stars are very bright objects. Planets do not generate their own energy through nuclear reactions. They reflect some of the radiation coming from their parent star.
Formation
Stars form when a cloud of dust and gas collapses under its own gravity. Planets form from material that accumulates in a disk orbiting a star during the early stages of its formation (when it is known as a "protostar").
The N11B star formation region captured by the Hubble Space Telescope
It is known that stars are composed of hydrogen and helium. Planets may be composed of a mixture of rock, metal, ice and water (like Earth) or gas that collects around a solid core of rock, ice or metal.
Planets
Planets orbit stars. So, the Earth, a planet, revolves around the Sun, a star. Two main characteristics distinguish a planet from other large objects such as the moon or an asteroid. First, the planet does not share its orbit with any other significant object (it has “cleared its surroundings”). Secondly, the planet is massive enough to have a rounded shape as a result of its own gravitational pull.
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune are classified as planets, while smaller objects such as Ceres (located in the Asteroid Belt) and Pluto are described as dwarf planets. Planets orbiting a star other than our Sun are called exoplanets or planets outside the Sun.
Brown dwarfs
There are some objects that have characteristics of both stars and planets. Known as brown dwarfs, they are larger than the largest planets (measured by mass) but smaller than the smallest stars. Too small to burn hydrogen in their cores, they cannot be considered true stars. Yet they form in the same way as stars - from clouds of interstellar gas - so they also cannot be considered planets. That's why astronomers say that brown dwarfs are neither stars nor planets. They are defined as special objects whose mass is 13 times greater than the mass of Jupiter, but less than 75 times.
How to distinguish a planet from a star?
Early observers could notice the difference between planets and stars in the night sky because the planets changed their positions from night to night against the background of stars, sometimes called the "celestial sphere." From Earth, stars always appear in fixed positions relative to each other. If you know where to look, you can easily chart the planets' positions from night to night. Planets appear as points of light, just like stars, although Venus is usually unmistakable as it is much brighter than any other night sky object except the Moon. One way to distinguish planets from stars is that planets almost never twinkle.
Comparative sizes of the brown dwarfs Gliese 229B and Teide 1 with Jupiter and the Sun.
Five planets can be seen with the naked eye: Mercury, Venus, Mars, Jupiter and Saturn. Mercury, which appears in the evening or morning but never in the middle of the night, is often difficult to detect because it is always close to the Sun.
Venus "overtakes" the Earth every 584 days in its orbit around the Sun. At the same time, it changes from the “Evening Star” (although it is a planet), visible after sunset, to the “Morning Star”, visible shortly before sunrise. Venus, after the Moon, the brightest object in the night sky, is usually considered by many to be an unidentified flying object (UFO).
The smallest known type of star is neutron star. Incredibly dense, they may only measure 20 km across, but have a mass roughly twice that of the Sun. A matchbox containing material from a neutron star would have a mass of about 13 million tons.
All brown dwarfs are about the same size as Jupiter, although their masses can be up to 75 times that of the giant planet.
Jupiter must be about 75 times more massive to become a star. With this mass, the hydrogen in its core will begin to undergo nuclear fusion, and Jupiter will generate its own energy.
