Match the words in the left-hand column to the appropriate blank in the sentences in the right-hand column. use each word only once. hints coma plasma tail oort cloud kuiper belt meteor shower nucleus 1. about a trillion comets are thought to be located far, far beyond pluto in the . 2. the bright spherical part of a comet observed when it is close to the sun is the . 3. a comet's stretches directly away from the sun. 4. a comet's is the frozen portion of a comet. 5. particles ejected from a comet can cause a(n) on earth. 6. the extends from about beyond the orbit of neptune to about twice the distance of neptune from the sun.

1. About a trillion comets are thought to be located far, far beyond pluto in the Oort cloud. Oort cloud is theoretical cloud of predominantly icy planetesimals and. Many scientists have a belief that it surrounds the Sun at the distance of approximately between 50,000 and 200,000 AU. Such forces as  passing stars and of the Milky Way usually easily affect the outer Oort cloud and dislodge comets right from their orbits through the Oort the cloud and then they send them to the the inner Solar System.
2. The bright spherical part of a comet observed when it is close to the sun is the coma. When coma is viewed by a telescope it looks quite fuzzy and, unlike the stars, it does not have legible form. Such a phenomenon as the coma is created when a comet comes too close to the sun, then a comet warms and sublimes its parts. These parts are placed  around  the nucleus of a comet forming sort of envelope.
3. A comet's plasma tail stretches directly away from the sun. Both coma and comet's tail are visible parts of a comet, and when the comet passes through the inner Solar System we it becomes visible right from Earth. Usually comets have two tails :the blue plasma tail and the red dust tail. The plasma tail is formed by an interaction between the solar wind and the cometary plasma. And the dust tail is caused due to the activity of solar radiation pressure directed to the cometary dust.

4. A comet's nucleus is the frozen portion of a comet. The conet nucleus is  the solid center of the head of a comet that is also called ''dirty snowball'' or an ''icy dirtball'' among astronomists. It consists of rock, dust, and frozen gases and when they are heated by the Sun they form a coma (which is an atmosphere that surrounds nucleus) by sublimating of the gases.

5. Particles ejected from a comet can cause a meteor shower on Earth. A meteor shower is a celestial phenomenon during which we can see how meteors radiate. The meteors which we can observe are formed by meteoroids that enter Earth's atmosphere at extremely high speeds and they usually move in parallel directions. Some of the meteors are too small and often don't even reach the surface of Earth as they disintegrate during the entering process.

6. The Kuiper Belt extends from about beyond the orbit of neptune to about twice the distance of neptune from the sun.  It is the circumstellar disc that uccurs in the Solar System beyond the already known planets. Its formreminds of asteroid belt, but it is far larger, to be more exact in 20 times. I