The comets of the solar system have always been of interest to space explorers. The question of what these phenomena are, worries people who are far from studying comets. Let's try to figure out what this celestial body looks like, whether it can affect the life of our planet. A comet is a celestial body formed in Space, the dimensions of which reach the scale of a small settlement. The composition of comets (cold gases, dust and debris) makes this phenomenon truly unique. The comet's tail leaves a trail that is estimated at millions of kilometers. This spectacle fascinates with its grandeur and leaves more questions than answers.
The concept of a comet as an element of the solar system
To understand this concept, one should start from the orbits of comets. Quite a few of these cosmic bodies pass through the solar system.
Let's consider in detail the features of comets:
- Comets are so-called snowballs that pass through their orbit and contain dusty, rocky and gaseous clusters.
- The heating of a celestial body occurs during the period of approach to the main star of the solar system.
- Comets do not have satellites that are characteristic of planets.
- Formation systems in the form of rings are also not typical for comets.
- It is difficult and sometimes unrealistic to determine the size of these celestial bodies.
- Comets don't support life. However, their composition can serve as a certain building material.
All of the above indicates that this phenomenon is being studied. This is evidenced by the presence of twenty missions for the study of objects. So far, observation is limited mainly to studies through super-powerful telescopes, but the prospects for discoveries in this area are very impressive.
Features of the structure of comets
The description of the comet can be divided into characteristics of the nucleus, coma and tail of the object. This suggests that the studied celestial body cannot be called a simple construction.
Comet nucleus
Almost all of the comet's mass is contained in the nucleus, which is the most difficult object to study. The reason is that the core is hidden even from the most powerful telescopes by the matter of the luminous plane.
There are 3 theories that consider the structure of the comet nucleus in different ways:
- Dirty Snow Theory … This assumption is the most widespread and belongs to the American scientist Fred Lawrence Whipple. According to this theory, the solid section of a comet is nothing more than a combination of ice and fragments of meteorite composition. According to this specialist, old comets and bodies of a younger formation are distinguished. Their structure is different due to the fact that more mature celestial bodies repeatedly approached the Sun, which melted their original composition.
- The core is made of dusty material … The theory was voiced at the beginning of the 21st century thanks to the study of the phenomenon by the American space station. This intelligence suggests that the core is a very loose dusty material with pores occupying most of its surface.
- The kernel cannot be a monolithic structure … Further, the hypotheses diverge: they imply a structure in the form of a snow swarm, blocks of stone-ice accumulations and a meteorite pile up due to the influence of planetary gravitations.
All theories have the right to be challenged or supported by scholars practicing in this area. Science does not stand still, therefore discoveries in the study of the structure of comets will stun for a long time with their unexpected finds.
Comet coma
Together with the nucleus, the head of the comet forms a coma, which is a hazy shell of light color. The trail of such a component of the comet stretches for a rather long distance: from one hundred thousand to almost one and a half million kilometers from the base of the object.
Three levels of coma can be identified, which look like this:
- The interior of the chemical, molecular and photochemical composition … Its structure is determined by the fact that in this area the main changes occurring with the comet are concentrated and most active. Chemical reactions, decay and ionization of neutrally charged particles - all this characterizes the processes that take place in the internal coma.
- Coma of radicals … Consists of molecules active in their chemical nature. In this area, there is no increased activity of substances, which is so characteristic of an internal coma. However, here, too, the process of decay and excitation of the described molecules continues in a quieter and smoother regime.
- Coma of atomic composition … It is also called ultraviolet. This region of the comet's atmosphere is observed in the Lyman-alpha hydrogen line in the distant ultraviolet spectral region.
The study of all these levels is important for a deeper study of such a phenomenon as comets of the solar system.
Comet tail
The comet's tail is a spectacle unique in its beauty and showiness. Usually it is directed from the Sun and looks like an elongated gas-dust plume. Such tails do not have clear boundaries, and we can say that their color gamut is close to full transparency.
Fedor Bredikhin proposed to classify sparkling trains according to the following subspecies:
- Straight and narrow tails … These components of the comet are directed from the main star of the solar system.
- Slightly deformed and wide-angle tails … These plumes deflect from the Sun.
- Short and highly deformed tails … This change is caused by a significant deviation from the main luminary of our system.
You can distinguish between the tails of comets and because of their formation, which looks like this:
- Dust tail … A distinctive visual feature of this element is that its glow has a characteristic reddish tint. A train of this format is homogeneous in structure, stretching for a million, or even ten million kilometers. It was formed due to numerous grains of dust, which the energy of the Sun has thrown over a long distance. The yellow tint of the tail is due to the scattering of dust particles by sunlight.
- Plasma structure tail … This plume is much more extensive than the dust one, because its length is calculated in tens, and sometimes hundreds of millions of kilometers. The comet interacts with the solar wind, from which a similar phenomenon occurs. As you know, solar vortex flows are penetrated by a large number of fields of the magnetic nature of the formation. They, in turn, collide with the comet's plasma, which leads to the creation of a pair of regions with diametrically different polarities. From time to time there is a spectacular break of this tail and the formation of a new one, which looks very impressive.
- Anti-tail … It appears according to a different scheme. The reason is that it is directed towards the sunny side. The influence of the solar wind on such a phenomenon is extremely small, because the plume contains large dust particles. It is possible to observe such an anti-tail only when the Earth crosses the comet's orbital plane. The disc-shaped formation surrounds the celestial body from almost all sides.
Many questions remain regarding such a concept as a cometary tail, which makes it possible to study this celestial body in more depth.
The main types of comets
The types of comets can be distinguished by the time of their revolution around the Sun:
- Short-period comets … The orbital time of such a comet does not exceed 200 years. At the maximum distance from the Sun, they have no tails, but only a barely perceptible coma. With a periodic approach to the main luminary, a plume appears. More than four hundred such comets have been recorded, among which there are short-period celestial bodies with a term of 3-10 years around the Sun.
- Comets with a long orbital period … The Oort cloud, according to scientists, periodically supplies such space guests. The orbital term of these phenomena exceeds two hundred years, which makes the study of such objects more problematic. Two hundred and fifty such aliens give reason to assert that in fact there are millions of them. Not all of them are so close to the main star of the system that it becomes possible to observe their activity.
The study of this issue will always attract specialists who want to comprehend the secrets of infinite outer space.
The most famous comets of the solar system
There are a large number of comets that pass through the solar system. But there are the most famous cosmic bodies that are worth talking about.
Halley's comet
Halley's comet became famous thanks to the observations of it by the famous researcher, after whom it got its name. It can be attributed to short-period bodies, because its return to the main luminary is calculated for a period of 75 years. It is worth noting the change in this indicator towards parameters that fluctuate within 74-79 years. Its celebrity lies in the fact that it is the first celestial body of this type, the orbit of which it was possible to calculate.
Certainly, some long-period comets are more spectacular, but 1P / Halley can be observed even with the naked eye. This factor makes this phenomenon unique and popular. Almost thirty recorded appearances of this comet delighted outside observers. Their frequency directly depends on the gravitational influence of large planets on the life of the described object.
The speed of Halley's comet in relation to our planet is amazing, because it exceeds all indicators of the activity of the celestial bodies of the solar system. The approach of the Earth's orbital system with the comet's orbit can be observed at two points. This leads to two dusty formations, which in turn form meteor showers called Aquarids and Oreanids.
If we consider the structure of such a body, then it is not much different from other comets. When approaching the Sun, the formation of a sparkling plume is observed. The comet's nucleus is relatively small, which may indicate a pile of debris in the form of building material for the base of the object.
It will be possible to enjoy the extraordinary spectacle of the passage of Halley's comet in the summer of 2061. Better visibility of the grand phenomenon is promised compared to the more than modest visit in 1986.
Comet Hale-Bopp
This is a fairly new discovery, which was made in July 1995. Two Space Explorers discovered this comet. Moreover, these scientists conducted separate searches from each other. There are many different opinions regarding the described body, but experts agree on the version that it is one of the brightest comets of the last century.
The phenomenality of this discovery lies in the fact that at the end of the 90s, the comet was observed without special devices for ten months, which in itself cannot but surprise.
The shell of the solid core of a celestial body is rather heterogeneous. Ice-covered areas of unmixed gases are combined with carbon oxide and other natural elements. The discovery of minerals that are characteristic of the structure of the earth's crust, and some meteorite formations, once again confirm that Comet Hale-Bop originated within our system.
The influence of comets on the life of the planet Earth
There are many hypotheses and assumptions regarding this relationship. There are some comparisons that are sensational.
Icelandic volcano Eyjafjallajokull began its active and destructive two-year activity, which surprised many scientists of that time. This happened almost immediately after the famous emperor Bonaparte saw the comet. This may be a coincidence, but there are other factors that make you wonder.
The previously described Halley's comet strangely influenced the activity of such volcanoes as Ruiz (Columbia), Taal (Philippines), Katmai (Alaska). The impact of this comet was felt by people living near the Cossouin volcano (Nicaragua), which began one of the most destructive activities of the millennium.
Comet Encke caused the most powerful eruption of the Krakatoa volcano. All this may depend on solar activity and the activity of comets, which provoke some nuclear reactions as they approach our planet.
Falling comets are quite rare. However, some experts believe that the Tunguska meteorite belongs to just such bodies. They cite the following facts as arguments:
- A couple of days before the catastrophe, the emergence of dawns was observed, which, with their variegation, testified to anomality.
- The appearance of such a phenomenon as white nights, in places unusual for it, immediately after the fall of a celestial body.
- The absence of such an indicator of meteoriticity as the presence of a solid substance of this configuration.
Today there is no likelihood of a repetition of such a collision, but do not forget that comets are objects whose trajectory can change.
What a comet looks like - watch the video:
The comets of the solar system is a fascinating topic that requires further study. Scientists all over the world, engaged in the study of the Cosmos, are trying to unravel the secrets that these celestial bodies of amazing beauty and power carry.
