Easy Astronomy Blog

The one thing we love the most worldwide of astronomy is a good puzzle. And if there had been ever a confusing and yet very powerful force of nature that we witness in the night skies, it is the coming of the mighty comet.

The arrival of a comet within view of Earth is an event of global significance. Witness the large media attention the Haley or Hale-Bopp have had when they have come within of these superb space objects is concurrently scary and awe inspiring.

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

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

Not as much is understood about comets. As a rule, comets are significantly bigger 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 diverse and changeable. The center or nucleus of a comet is generally quiet solid but the “snowball” materials frequently make a “cloud” around that nucleus that may 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 superb tail that makes it so exciting to observe when a comet comes inside view of Earth.

The origins of comets is similarly puzzling. a number of theories about where they come from but it is clear where they originate 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 wrapped 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 of 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, thanks to the strong gravitational orbits of the many planets in our 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 a comet that is expected to burn out or impact the sun within two hundred years as a brief period comet whereas a long period comet has a life expectancy of over two hundred years. That comet that is anticipated to us as earth dwellers but in terms of stars and planets, this could be a brief period comet while a space object indeed.

Scientists across the globe have put together some pretty impressive probes to find out more about comets to help our understanding of these visitors from beyond. In 1985, for instance, the United States put a probe into the path of the comet Giacobini-Zinner which passed through the comets tail gathering tremendous scientific knowledge about comets. Then in 1986, a global collation of scientists managed to launch a probe that was able to fly close to Haley’s comet as it passed near Earth and continue the research.

While science fiction writers and tabloid newspapers like to alarm us with the possibility of a comet impacting the earth, scientists who understand the a world collation of comets and what changes their trails let us this is improbable. That is good because some comets reach sizes that are the size of a planet so that impact would be ravaging. For the moment, we will 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 do you know about Jupiter, Venus, or Mars? At planet-facts.com, all the important facts are there and you can compare all nine planets in our solar system. Make sure to also read about planet Pluto facts.