Comets are small Solar system objects that move in orbit around the Sun and can be observed as a bright point with a long tail. They are interesting for several reasons.
Since ancient times people have observed comets in the sky. Only once in 10 years, we can see the comet from Earth with the naked eye. Its impressive tail flashes across the sky for several days or weeks.
In ancient times comets were considered a curse or a sign of previous trouble. So in 1910, when the Ground caught the tail of Halley’s comet, some entrepreneurs took advantage of the situation and sold people masks, pills from the comet, as well as umbrellas to protect from comets.
The name of the comet received from the Greek word for “long-haired” because people in Ancient Greece thought that comets look like stars with flowing hair.
Comets tail appears only when they are close to the Sun. When they are far away from the Sun, comets are extremely dark, cold, icy objects. Ice body is called the nucleus. Continue reading
Space when observed with the naked eye
Comets and meteors
Unlike stars and planets that the naked eye perceives as a luminous point, the comet is observed in the form of an elongated spot, in which through careful observation can see the relatively bright concentration – “head” and a conical “tail”. With the aid of the telescope each year find 5-10 comets, but rarely any of them are so bright that accessible to observation with the naked eye. Like planets, comets move around the Sun. But unlike the planetary orbits of the trajectory of comets typically have very elongated. The periods of revolution around the Sun fills the interval from a few years (comet Encke is for 3.28 years) to several thousand years (comet Hale-BOPP – 3000 years).
The comet nucleus, from which emerge jets of gas, plasma and dust all the more intense, the closer to the perfect Sun the comet is a huge (from kilometers to tens of kilometers in diameter) snowball. It is composed of molecules containing hydrogen, oxygen (e.g., H 2 O), carbon and nitrogen, as well as from dust, which escapes as ice sublimation (i.e., in the transition to the gaseous state under the action of radiation of the Sun). In the core there are larger solid particles. Continue reading
The sun is an ordinary star, whose age is about 5 billion years. On the Sun’s surface temperature is about 5.5 degrees Celsius, in the center, it reaches 14 million degrees. The sun is a huge ball of gas, the diameter of which is almost 109 times the diameter of Earth. But in relation to other stars the Sun is not too big.
The yellow light of the Sun comes from the layer of the solar atmosphere, having a thickness of 500 km and is called the Photosphere. Almost all solar energy, including heat and light, comes to us from the Photosphere, although it originally produced in the depths of the Sun.
The surface of the Sun — blistered. These bubbles, or foam, is called the solar fraction. Due to convection in the solar atmosphere, the thermal energy from the lower layers is transferred to the Photosphere, giving it a foamy structure. In the 1960s, astronomers found that the upper atmosphere of the Sun approximately once every five minutes is raised and lowered. So the Sun seems to vibrate. By studying these vibrations, astronomers hope to find out what is inside a sun ball. Continue reading