The one thing we love the most in the world of astronomy is a good poser. And if there was ever a mysterious and yet very powerful force of nature that we witness in the night skies, it’s the coming of the mighty comet.

The arrival of a comet within view of Earth is an event of global importance. Witness the huge media attention that the Haley or Hale-Bopp have had when they have come within of these superb space objects is simultaneously frightening and shock provoking.

Above all, it is during these comet viewings that the astronomer comes out in all of us. But what is a comet? Where did it come from? And how does it get that wonderful tail?

We should never confuse comets with asteroids. Asteroids are small space rocks that come from an asteroid belt between Mars and Jupiter. While still quite surprising to see, they diminish in comparison to the arriving of a comet. Asteroids also have received substantial study by the systematic community.

Not as much is known about comets. As a rule, comets are considerably larger than asteroids. The composition of a comet is a mixture of nebulous, gasses, ice, dust and space waste. One scientist called the composition of a comet as similar to a “dirty snowball” as the composition is so various and changeable. The center or nucleus of a comet is generally quiet solid but the “snowball” materials often create a “cloud” around that nucleus that will become quite giant and that extends at great lengths behind the comet as it moves through space. That trailing plume is what makes up the comet’s magnificent tail that makes it so exciting to observe when a comet comes inside view of Earth.

The origins of comets is similarly mysterious. There are a number of theories about where they come from but it is clear that they come from outside our solar system, somewhere in deep space. Some have speculated they are fragments left over from the organization of planets that get loose from whatever gravitational pull and are sent flying across space to ultimately get caught up in the gravity of our sun bringing them into our solar system.

Another theory is they come from a gaseous cloud called the Oort cloud which is cooling out there after the organization gaseous cloud called the sun. As this space debris cools, it is getting arranged into one body which then gathers acceptable mass to be attracted into the gravity of our solar system turning into a fast moving comet plunging toward our sun. However, because of the robust gravitational orbits of the various solar system, the comet does not always right away collide with the sun and often takes on an orbit of its own.

The life expectancy of comets varies widely. Scientists refer to solar system, the comet that is expected to burn out or impact the sun within 2 hundred years as a brief period comet whereas a long period comet has a life expectancy of over two hundred years. That may appear to us as earth dwellers but re stars and planets, this as a brief period comet while a space object indeed.

Scientists across the world have put together some pretty inspiring probes to find out more about long to aid our knowledge of these visitors from beyond. In 1985, for instance, the United States put a probe into the trail of the comet Giacobini-Zinner which passed through the comets tail gathering amazing systematic data about comets. Then in 1986, an international collation of scientists managed to launch a probe that was ready to fly close to Haley’s comet as it passed near Earth Put a probe into the research.

While science fiction writers and tabloid papers like to alarm us with the possibility of a comet impacting the earth, scientists who understand the orbits of comets and what changes their paths probe us this is improbable. That is good because some comets reach sizes that are the size of a planet so that impact would be devastating. For now, we can enjoy the fun of seeing comets make their rare visits to our night sky and marvel earth, scientists who understand the spectacular shows that these visitors from beyond put on when they are visible in the cosmos.

What is the biggest known planet in our galaxy? Visit planet-facts.com to compare the nine planets in our solar system. You might also want to take a look at the planet Pluto.