The movement of planets around the sun and the moons movement around our earth are depicted by models collectively called orreries. If you wish to buy such an item, there are many things to take into consideration. So when you find an orrery for sale it is worth making comparisons to establish its true worth.
The usual things you would look at are condition, size and the movement but there is much more to consider. The materials they are made of can make a difference to the value and the amount of moons and planets they contain is obviously a large factor. They can be as little as our earth and moon revolving around the sun and each other or complex enough to show all the planets and a variety of their moons.
These were originally created as scientific instruments to show the relevant movement of planets and moons as they travel through their orbits. Not all of them show the whole solar system but in the case of older models they may show the complete system as it was known at that time.
There are so many names for these gadgets that it is difficult to know them all. Originally they were known as planetariums but this has now been used more in the description of large domed rooms where the sky is projected onto the ceiling to allow people to see it in detail. Different names are applied to certain collections of planets, so you will need to decide which variation of planets you would like and what the appropriate name is for that version.
Depicting the way each planet moves on its orbit and at its speed. The movement shows the progress through time of each planet and their relevant moons. They also show the different tilt of each planet on their axis and the planet rotations. As you can see the work involved in building these items is becoming quite demanding.
Quite often these are driven by clockwork and gears move the planets and moons accordingly. The movement shows the distances between planets at different times in the cycle as they get closer or further away from each other, and as the whole movement unfolds many interesting things can be noted such as solar and lunar eclipses.
To create a full model of the planets and all their attending moons that we are now aware of would be a major feat, especially when you consider that Saturn and Jupiter both have more than 60 moons apiece. It is understandable then that only certain parts are depicted on most orreries and they vary widely. It is also true that they are not built to scale as the vast variance in sizes of planets and moons and the distances between make that almost impossible. The orbits are also not totally accurate, as the gearing represents full cycles when orbits are very rarely that accurate.
So when you are looking for an orrery for sale you should now be able to identify the differences in what is available and match them to what you personally require. Whether you want a large detailed item or a small less complex one in a valuable metal you should be able to find something relevant. Knowing that you are paying the right price for the particular version you require.
The usual things you would look at are condition, size and the movement but there is much more to consider. The materials they are made of can make a difference to the value and the amount of moons and planets they contain is obviously a large factor. They can be as little as our earth and moon revolving around the sun and each other or complex enough to show all the planets and a variety of their moons.
These were originally created as scientific instruments to show the relevant movement of planets and moons as they travel through their orbits. Not all of them show the whole solar system but in the case of older models they may show the complete system as it was known at that time.
There are so many names for these gadgets that it is difficult to know them all. Originally they were known as planetariums but this has now been used more in the description of large domed rooms where the sky is projected onto the ceiling to allow people to see it in detail. Different names are applied to certain collections of planets, so you will need to decide which variation of planets you would like and what the appropriate name is for that version.
Depicting the way each planet moves on its orbit and at its speed. The movement shows the progress through time of each planet and their relevant moons. They also show the different tilt of each planet on their axis and the planet rotations. As you can see the work involved in building these items is becoming quite demanding.
Quite often these are driven by clockwork and gears move the planets and moons accordingly. The movement shows the distances between planets at different times in the cycle as they get closer or further away from each other, and as the whole movement unfolds many interesting things can be noted such as solar and lunar eclipses.
To create a full model of the planets and all their attending moons that we are now aware of would be a major feat, especially when you consider that Saturn and Jupiter both have more than 60 moons apiece. It is understandable then that only certain parts are depicted on most orreries and they vary widely. It is also true that they are not built to scale as the vast variance in sizes of planets and moons and the distances between make that almost impossible. The orbits are also not totally accurate, as the gearing represents full cycles when orbits are very rarely that accurate.
So when you are looking for an orrery for sale you should now be able to identify the differences in what is available and match them to what you personally require. Whether you want a large detailed item or a small less complex one in a valuable metal you should be able to find something relevant. Knowing that you are paying the right price for the particular version you require.
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When you are shopping for unique orrery for sale way to find what you need is to go online. Use this web store at http://www.orrerystore.com and order your items today!
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