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.

Whether you are a beginner or old pro at scanning the stars and planets, you are probably aware that there are different types of telescopes used for star gazing.  If you haven’t guessed already, it is the refracting and reflecting telescopes that reflect the two basic models of telescopes utilized by today’s neophyte and professional star gazers.   Of these two telescopes, the refracting telescope has a history dating back centuries as our ancestors used this type of telescope to explore the heavens.   This telescopes origins can be traced back to the 15th century and is still a very important telescope design in the twenty-first century.  The truth be known, the refractor telescope is one of the oldest telescope designs still in use by today’s astronomers.

The Basics of a Refractor Telescope

The refracting telescope, also known as a refractor telscope, has multiple concave lenses which allow the incoming light to be refracted, resulting in images that are more distinct and greater in size.  These qualities give the appearance that the actual images appear much bigger than viewing with the naked eye.   These refractors gather the incoming light and bend it, allowing you to view objects from a distance.  This magnification is what provides you with the ability to clearly view the stars and night sky. Even though refracting telescopes may have a lot of bells and whistles, the reality is that they are just a series of concave lenses that refract the light.

The Advantages of a Refracting Telescope

This is a well tested and constantly improved design that has endured for centuries.   Throuhout the years, its design was constantly tweaked, resulting in continuous improvement of its design and magnification characteristics.  This was a helpful, providing astronomers with the opportunity to determine the refracting telescope design’s strengths and weaknesses.

It’s well known that the design of the refracting telescope has been improved dramatically since the fifteenth century.  Even with the improvement of refractor technology, it is the size of the refractor telescope that still poses a potential concern.  The need to dramatically increase magnification for astronomical research has resulted in larger and larger lens size.  This can result in the potential for defects or sagging.

The truth is that refracting telescopes have proven themselves across the centuries and, to attest to their value, have remained one of the most popular designs among astronomers.  Regardless of the type of telescope you choose to scan the cosmos, the ongoing use and popularity of the refracting telescope provides assurance that it will be with us for decades to come.

Buying a Refracting Telescope

Your quest to find the ideal refractor telescope at an affordable price can seem like a daunting task.  But what we found was that visiting telescope and astronomy websites that provide telescope user reviews can be very helpful in making your decision.  So, whether you are considering a child telescope or professional model, be sure to do your research and you will be assured of enjoying many hours of star gazing pleasure.

Most everyone has heard of Stonehenge, the stone circle in England that has been portrayed as an astronomers’ tool, a grave yard, a druidic sacrificial altar, and even in some movies and television programs as a portal to other dimensions and other worlds. But although famous, Stonehenge isn’t unique. There are other such stone circles all over the world, many containing one astronomy henge stone or even an entire grouping of them. The term henge is derived from the Old English word, henge, that became part of the Stonehenge name. Henge doesn’t mean circle or stone or earthwork, it means hang. It refers to the Stonehenge site specifically as horizontal stones were hung around the circle by placing them on top of vertical stone pillars. The name eventually came to denote a variety of similar sites, generally populated by some sort of stone formation within an earthen circle. But a henge only refers to stones set within an earthen circle. Without the earthen circle, either raised or dropped to be lower than the surrounding ground, it isn’t a henge, but rather a stone circle.

While many of these stone henges, including the famous Stonehenge, were used as burial grounds and sacrificial sites, almost all of them have some element related to astronomy. It’s sometimes argued whether or not these stone formations were built for astronomy first, but there’s no doubt of building skill and scientific know how that went into erecting them. The elements that have to do with astronomy include the markings of important dates, such as the summer or winter solstice, when the sun would rise at a point marked exactly by a stone placement. This might include the sun being viewable through a tiny window at sunrise from a point at the center of a circle. Stonehenge has an amazing array of astronomical measures built into the circle. It really doesn’t matter if they were the purpose for the site or added later. They’re still amazing.

A lesser known but no less spectacular henge is the Avebury Henge located in Wiltshire. The henge neighbors a number of other smaller stone circles, and encompasses the entire town of Avebury. It is believed that this henge had astronomical purposes as many of its stones, now mostly fallen, had positions that corresponded with key phenomenon. But it also had a relationship to ancestral and gender worship as the stones come in two main types : tall, slender stones and short, squat stones  that may have represented female and male archetypes. Some archaeologists dispute this, however, claiming the stones were chosen for no other reason than their beauty and size.

It may be a compelling idea to grab an authentic astronomy henge stone to set up in your living room. Aside from the fact that many of these weigh many tons, they completely lose their significance when removed from the earthen circle. Instead, set up your own stone henge at home.