Comets are amazing cosmic phenomena that can sometimes be observed from the surface of the Earth with the naked eye. What comets consist of, what laws do they obey, and why does the movement of these celestial bodies follow a certain trajectory?
What is a comet?
Comet - This is a small-sized space body, which consists of stone, metal, ice (in compressed form), and moves around the Sun in an elongated orbit with a certain period.
A distinctive feature of the comet is the presence of a luminous gas and dust tail and coma. They arise when the body approaches the largest star in our system. While the comet moves in the middle of outer space, it is not possible to consider it.
Components of the comet:
- Core. It occupies most of the entire mass of the comet. It is located in the center and has a high density. According to one theory, it consists mainly of compressed ice with particles of meteor material. According to other observations, dust predominates in the composition.
- Coma. A misty shell around the core, having a cup shape. The coma has a gas and dust composition and is divided into three parts: internal, visible, ultraviolet. Size ranges from 100,000 - 1,400,000 km. In combination with the nucleus, the coma represents the head of the comet.
- Tail. The luminous part of the comet, which can have various parameters and shapes. The tail consists of small particles of dust and gas, so it does not have clear boundaries.It is formed under the influence of the solar wind. Gaseous particles become visible only near the Sun, since they undergo intense heating and evaporation (under the influence of ultraviolet radiation).
Interesting fact: in 2014, the first ever spacecraft landing on the surface of a comet took place. The Rosetta interplanetary station was launched in 2004. It took 10 years to enter the orbit of the comet Churyumov-Gerasimenko, get closer to it and make a landing. Thanks to this event, scientists received a lot of valuable information about the comet.
Where do comets come from? They arrive from the Kopeira belt, as well as the Oort clouds. The Kopeira belt is represented by the asteroid belt, which is located beyond the orbit of the planet Neptune. The Oort cloud is an accumulation of small celestial bodies located on the border of the solar system far from all planets.
How are comets handled?
For many years, they can move far from the sun. But sometimes two comets collide or fly very close to each other. As a result, the trajectory of movement changes - the comet may begin to head towards our star.
Gradually approaching the Sun, the cosmic body more and more feels the force of attraction. Because of this, the speed of the comet increases even more. At a sufficiently close distance to the Sun, gas heating occurs, and the comet becomes visible.
Comets move in different orbits in the shape of a cone. The core obeys the laws of celestial mechanics. Thus, when a comet passes near a planet, it is affected by gravity. Thus, the body accelerates in a certain direction.Therefore, cometary orbits have elongated shapes, in contrast to the elliptical orbits of the planets of the solar system.
Interesting fact: Comet Halley is considered the most famous. She returns to the Sun every 75 years. You can see it even with the naked eye. The last time a comet was observed in 1986. The next alleged appearance is July 2061.
Comets are divided into two types according to the frequency of revolution around the star: short-period (up to 200 years) and long-period (over 200 years).
Comets can repeatedly revolve around the Sun or appear only once - this also depends on the trajectory. In addition, underweight bodies can completely evaporate when exposed to sunlight. Sometimes comets even fall into several parts. This is due to the loose structure of some bodies.
The main component of the comet is the nucleus, which moves in orbit. It is subject to the laws of celestial mechanics, which determine the motion of a nucleus in outer space. Usually comets move far from the Sun, but sometimes they collide and, under a combination of circumstances, change the trajectory of movement. The core is in the gravitational field of other cosmic bodies, with a more significant mass. Among them are the planets of the solar system and the sun itself. Thus, the trajectory of a comet is the orbit of its nucleus.
