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How To Choose A Telescope

Dec 072011

There are many different types of telescopes, besides many different makes, and these different sorts are manufactured to perform different duties. Therefore, before leaping in and buying a telescope you have to learn how to buy a telescope first.

However, you can cut out a lot of futile searching and comparing if you can answer two vital questions before you begin, namely: what do you want the telescope for and how much can you afford to spend?

In many ways, it is best to start with a quite simple telescope, realize what its failings are for what you would like a telescope for and then trade up into the right sort of telescope. Another decent manner to start is with a pair of binoculars and then purchase a telescope that suits your interests. Binoculars will disclose a great deal more that the naked eye – it is quite surprising how much.

If you would like to use your optical aid for a number of purposes such as bird-watching and astronomy, then binoculars are almost certainly the answer until you choose to specialize in astronomy, when you can get a telescope dedicated to that hobby and its tremendous distances.

The eyepiece is the most vital part of a telescope and you will want one with adjustable magnification. The quality of this lens is vital: the view through it ought to be crisp and clear with very little to no chromatic aberration. Chromatic aberration is a form of colour distortion that manifests itself as halos around outstandingly bright lights.

Knowing where you will be utilizing your telescope is also important, because of adverse factors in cities. The skies over cities are frequently polluted with contaminants like smoke or smog, but they are always polluted with street light. This street light pollution can be a real nuisance, so ask if your telescope can be fitted with filters to mask out these pollutants.

A telescope has to collect light in order for you to see through it. This is accomplished by the primary lens and the amount of light that the telescope collects is in direct proportion to the size of this primary lens or objective. If you would like more light, you need an objective with a larger surface area.

Light is needed more than magnification sometimes, particularly while looking at the stars because of the distances concerned. It actually scarcely matters whether you are magnifying a star 10 or 12 times when it is 1,000 light years away. However, what you can see, you need to be able to see clearly.

Too much magnification can make directing the telescope very difficult for novices unless there is a ‘sight’. This is a weaker lens outside the prime telescope that makes it easier to direct at the item that you want to look at.

It is not possible to cover all the aspects of purchasing your first star-gazing telescope in a short piece, so be prepared to do some more research.

Owen Jones, the writer of this piece, writes on a variety of subjects, but is now involved with the kids building set. If you would like to know more, please visit our website at Smart Toys for Kids.

The Night Sky

Astronomy No Responses »

Oct 242011

The first time that you gaze up into the night sky and feel the marvel of the universe is the time when most people, even the most revered professional astronomers, think back to if they think about their early interest in the stars. It is usually a very special moment, when an adult led you by the hand, pointed at the sky and said: ‘Look, that is the Pole Star’.

Country folk will almost certainly discover the night sky at an earlier time than city dwellers because the atmosphere above a city is normally so polluted that you cannot see the stars from below. There are two kinds of pollutants that prevent you from seeing the stars in a city, smoke and light. Street lights give off a corona that prevents you from seeing the weaker light from the stars beyond.

If you want to evoke that instant in your life, why not take a child out into the country to look at the stars one night? If you have a pair of binoculars, so much the better, but they are not vital. If you have forgotten which stars are which, take a book on the topic or a map of the night sky. These days you can download a map of the night’s sky for the day that you want.

The night sky actually changes every night. The stars and the constellations do not move much, so you should not have too much difficulty finding them, but if a planet is passing by, it will be in a different part of the sky each night, which is why it is helpful to get an up-to-date map of the night sky for the date you want to go star gazing.

One of the hardest concepts for a child (or anyone else for that matter to grasp is the magnitude of the universe – the sheer size of it. Here are a couple of facts that will amaze most individuals:

1] Our Sun is a star in the galaxy called the Milky Way and it has its own planets revolving around it. However, there are estimated to be 100,000,000,000 (one hundred billion) stars similar to our Sun in the Milky Way.

2] The Milky Way is one of approximately tens of billions of galaxies in the universe and the Milky Way is one of the smaller galaxies.

3] It would take over 100,000 years to go from one edge of the Milky Way to the other, if you were travelling at more than five trillion miles per year or more than 570 billion miles per hour.

4] It has been calculated that our Milky Way is 14,000,000,000 (fourteen billion) years old

It is very hard to comprehend astronomical numbers like this but this might help:

1 billion seconds ago, it was 1980

1 billion minutes ago, Jesus had only just passed away

1 billion hours ago, mankind was not yet on the planet

Owen Jones, the writer of this piece, writes on a number of subjects, but is now involved with the kids building set. If you would like to know more, please visit our website at Smart Toys for Kids.

The Most Amazing Hobby On The Planet

Astronomy No Responses »

Oct 052011

There are thousands of hobbies, aren’t there? Some appear pointless, others offer a chance for self-improvement and others offer the chance to create some money, but what is the most amazing hobby of them all?

It is so amazing that the overwhelming majority of individuals on the planet have taken part in it and do on a ordinary basis. It fascinates millions of individuals every day.

Or ought I to say each night, because I am referring to amateur astronomy or, more basically, star gazing. Every sighted person in the world throughout the history of mankind, has looked up at the planets and the stars in the night sky and wondered something. Individuals ask themselves different questions, but everyone has thought about something whilst gazing at the stars.

Astronomy is a fantastic hobby that surely everybody is interested in. It is there to do, free of charge most nights of the week if the sky is clear. If you would like to see more, you can buy a pair of binoculars and if you would like to study items even further away, you can get a telescope.

Neither of these optical aids is highly costly at the entry stage, but the difference they can make to your degree of enjoyment of the hobby is, well, amazing.

Books on astronomy are not expensive and they will point the greenhorn in the right direction for seeing all types of amazing sights: constellations, planets, meteor storms, visiting comets etc..

There is also a wealth of free knowledge on line. Join Jodrell Bank (the British Observatory) on Twitter to be kept informed about what is happening in the night sky in the near future in your region.

This is a different fascinating aspect of this hobby, visiting observatories, where you get the opportunity to observe the universe from as close as we can get and still be on terra firma. If you have never looked at the night sky through a huge telescope (or even any telescope), you have a colossal pleasure in store for yourself.

Children adore astronomy and I have heard many well-known astronomers say that their love of astronomy started when a relative pointed to the night sky and explained something to them. This led to taking out library books on astronomy and asking for a telescope for Christmas. Twenty years later they are on television explaining some astronomical fact to the nation.

That is amazing. Not many chess players or stamp collectors or football fans can say the same. And there is still such a lot to learn about the solar system. Everyone has a opportunity to try to explain something. Even though most of the ‘easy stuff’ has already been discovered, it has not all been explained to the satisfaction of all astronomers.

If you are not so interested in astronomy yourself or do not have the time, why not give the chance to some child you know? Instead of the usual Christmas or birthday gifts, give a book on astronomy, binoculars or a telescope, you could be encouraging the next Patrick Moore, but at least you will be introducing someone to the most amazing hobby in the world or even in the universe.

Owen Jones, the author of this piece, writes on a variety of subjects, but is now involved with the kids building set. If you would like to know more, please visit our website at Smart Toys for Kids.

Calendars And How To Appreciate Them

Astronomy No Responses »

Jul 132010

The calendar is such a commonplace, everyday item, but how much do you really know about the operation of it. Why is it like that?

A DAY: The Earth rotates at a reasonably fixed pace about the imaginary line running between the North and South Poles named the Earth’s Axis. The time it takes to spin once is called a ‘rotation’ and this takes just under twenty-four hours. Nevertheless, because the Earth is constantly traveling around the Sun, the exact time from noon one day to noon the next is 3 minutes 56 seconds longer and this makes a day almost exactly twenty-four hours in length.

The actual time from noon to noon varies depending where the Earth is on its celestial course around the Sun, but if you average the days in a year out, it comes to exactly twenty-four hours.

A YEAR: All nine planets in our solar system travel around the Sun in almost perfectly circular routes called orbits. Each trip around the Sun is called a revolution and all the planets revolve around the Sun in the same direction. The direction the Earth takes can be verified by noting its location against the background stars.

Since you cannot see the Sun and the stars at the same time, it is obligatory to note the location of the Sun in the morning and the see which stars appear there in the night. You will see that the Sun appears to pass through the twelve constellations of the zodiac during a year.

Earth’s journey around the Sun, which seems like the Sun travelling through the zodiac takes about 365.25 days. This is different from year to year, so astronomers add or delete a second in some years to keep their time accurate with the Earth’s motion.

THE SEASONS: The seasons indicate the variation in the pattern of daylight over the course of a year. Because the Earth is tilted off centre, different parts of it get different amounts of sunlight on different stages of its path around the Sun, a path that we call a year. So, between about the 21st September and late March, the Earth’s Northern Hemisphere is tilted away from the Sun, which creates Autumn and Winter, giving less than twelve hours of daylight per day.

From April to the 20th September, the Northern Hemisphere receives more than twelve hours of daylight a day, producing Spring and Summer. The exact opposite occurs in the Southern Hemisphere.

The Equinoxes take place at the points in the year when there is exactly twelve hours of sunlight and darkness in the day. So, the vernal or Spring equinox is on or around the 21st March and the autumnal equinox is on or around the 21st September. Summer officially commences on the day with the greatest amount of daylight, the 21st June or summer solstice.

The winter solstice occurs on the shortest day, the 21st December. ‘Solstice’ is a combination of two words meaning ‘sun standing still’ and the days are so called because they are the days when the apparent movement of the Sun reaches its limits and reverses course again.

Owen Jones, the author of this piece, writes on many topics, but is currently involved with researching Franklin planner pages. If you have an interest in calendars, organizers or promotional calendars, please go over to our web site now at Promotional Desk Calendars

Calendars – Why They Can Be Slightly Out

Astronomy No Responses »

Jul 122010

Thousands of years ago, ancient Greek astronomers calculated that the track of the Earth’s axis is constantly, even if in a very slow way, shifting in a uniform pattern. The variation is very similar to the manner a spinning top slowly leans one way and then another as it slows down. It is a wobble that happens as its axis alters direction.

This odd movement of the planet is due to several factors, the most significant of which is something called ‘precession’. Precession stems from the fact that the Earth is not a flawless sphere. It is in fact about twenty-seven miles longer around the Equator that it is about the Poles. The Earth then is oblate, or fat around the middle like middle-aged spread, but it is due to the rotation not to its age.

If you imagine the Earth with its Poles off centre. Then rotate that image and you will find that any point, except the very centre of the axis, will move in a circle. But very, very slowly. So slowly that it takes 26,000 years to go full circle and get back to where it started from.

This point then, any point you choose, is very gradually shifting its position in relation to the stars because the axis is rotating too. The result of this is that, what we call the North Star (formally known as Polaris, which is in fact one degree off true North) will not be over our North Pole one day. In fact, by about 15,000 AD, Vega will be almost over the North Pole, although it will be about four degrees off true North. But even this will not endure, and by 28,000 AD, Polaris will be back above where it is nowadays.

One of the effects of the precession is that seasons vary. They modify the dates that they take place, so that Summer could come earlier or later. The amazing thing about our calendar is that it is corrected for that (with the leap year). If it were not, the vernal or Spring equinox would shift over 13,000 years from March 21st to September 21st., which is the date of the autumnal equinox, precisely half a year later.

It is for this reason that the precession of the Earth is generally referred to as the “Precession of the Equinoxes”. Although the precession of the equinoxes is very gradual, it can be readily seen. The correct year of 325.25 days is the length of time from one vernal equinox to the next vernal equinox, however, it takes 20 minutes and 24 seconds longer for the Sun to appear in exactly the same position with relation to the stars behind it over the same period. It is for this reason that accurate star maps have to be stamped with the exact time and date to which they relate.

Older Entries

World Wide SETI

How To Choose A Telescope

The Night Sky

The Most Amazing Hobby On The Planet

Calendars And How To Appreciate Them

Calendars – Why They Can Be Slightly Out

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