Interesting facts about comets
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. It is 90 % of the mass of the comet. The core consists of various types of ice, dirt and dust. In turn, ice includes frozen water, and admixture of different gases, such as ammonia, carbon, etc. matani And in the center is a small core of stone.
While it approaches the Sun, the ICES start to heat up and vaporize, releasing the gases and dust particles that form a cloud or atmosphere around the comet called a coma. When the comet continues to move closer to the Sun, dust particles and other debris in the coma begin to deflate due to the pressure of sunlight from the Sun. This process forms a dust tail.
If the tail is bright enough we can see it from the Ground, when the sunlight reflects off dust particles. As a rule, comets have a second tail. It’s called ion or gas, and it is formed when the ice core are heated and turn directly into gases without going through the liquid phase – a process called sublimation. The residual gas can be seen due to the glow caused by solar radiation.
After the comets start to move in the opposite direction from the Sun, their activity is reduced, and the coma and tails disappear. They turn into a simple ice core again. And when the orbits of the comets will again return them to the Sun, the head and tails of comets begin to form again.
Comets have a wide range of sizes. The small comets may have a kernel size of up to 16 kilometers. The largest nucleus observed is about 40 kilometers in diameter. Tails of dust and ions can be huge. Ion tail of comet Hyakutake stretched at a distance of about 580 million kilometers.
There are many versions of the formation of the comets, but the most common one that comets arose from the remnants of substances in the formation of the Solar system.
Some scientists believe that comets brought to Earth the water and organic matter, which became the source of the origin of life.
The meteor shower can be observed when the Earth’s orbit crosses a trail of debris left by the comet behind him.
No one knows how many comets there are. as most have never seen. But there is a cluster of comets called the Belt of Kuiper located at 480 million kilometers from Pluto. There is one such cluster that surrounds the Solar system called the Oort Cloud – there can be more than a trillion comets, which move in a different direction. As of 2010, astronomers have discovered about 4,000 comets in our solar system .
More to see the comet – it is a miracle that many people dream to see at least once in your life. But in extremely rare cases, comets can cause problems on Earth. Most scientists believe that a very large asteroid or comet could hit the Earth approximately 65 million years ago. As a result, caused changes on Earth led to the extinction of the dinosaurs. Very large asteroids, as well as very large comets, could cause severe damage if it reached the Earth. However, scientists believe that large impacts. like the ones that killed the dinosaurs occur once in several hundred million years.
Comets can change the direction of flight for several reasons. If they pass close enough to a planet, the tug of gravity that the planet may slightly change the path of the comet. Jupiter, the largest planet, is the most suitable planet to change the path of the comet. Telescopes and spacecraft recorded images of at least one of comet shoemaker-levy 9 – shattered from hitting the atmosphere of Jupiter. In addition, sometimes the comet moving toward the Sun, fall right into it.
Over millions of years, most of the gravitational comets fly beyond the Solar system or lose their ice and disintegrate while driving.