Product Name: KX1908 Space Instrument (Three-Sphere Instrument)
Item No. : KX1908
Dimensions: 120*120*110mm
Weight: Approximately 150g
Material: Wood + Battery box + reduction motor + shaft + foam ball...
Packing: 200 pcs
Box specification: 600*550*450mm
Note: The product is in natural wood color. The color on it is painted with acrylic paint and needs to be purchased separately.

The model of the movement laws among the Sun, the Earth and the Moon is the three-sphere instrument.
The Earth-Moon-Sun motion demonstration model is a simple three-ball instrument model toy, which can vividly depict the relative motion among the earth, the moon and the sun in an intuitive teaching model.
It's very interesting that children can make the Earth, moon and sun in the model move according to the real laws of movement by hand!

The three-sphere instrument is composed of three small spheres representing the Sun, the Earth and the Moon, and is equipped with a mechanical linkage device to demonstrate the relationship among the three spheres and some astronomical phenomena resulting from it. To imitate the real situation in nature, the sun in the middle usually uses luminous bulbs to illuminate the Earth and the Moon. The Earth orbits the Sun at an incline, and the orbit of the Moon around the Earth intersects with that of the Earth around the Sun at an Angle. In this way, phenomena such as solar and lunar eclipses, the waxing and waning of the moon, the rotation and revolution of the Earth, and the alternation of day and night and the four seasons can be demonstrated.

The utility model aims to provide a model of the operation of the Earth-Moon system, which can not only objectively reflect the spatial positions of the Sun, the Earth and the Moon, but also visually and systematically demonstrate the operation of the Sun, the Earth and the Moon, as well as various natural phenomena produced by the mutual movement of these three celestial bodies.
The Earth revolves around the Sun, completing one revolution approximately every 365 days. The moon orbits the earth, completing one revolution approximately every 365 days. And they all have their own rotation.

A lunar eclipse is a special astronomical phenomenon. It occurs when the moon moves into the shadow of the Earth. In the area between the Moon and the Earth, due to the sunlight being blocked by the Earth, a part of the moon appears missing. At this moment, the Sun, the Earth and the Moon are exactly (or almost) in a straight line. Lunar eclipses can be classified into three types: partial lunar eclipses, total lunar eclipses and penumbral lunar eclipses. A lunar eclipse can only occur around the 15th day of the lunar month.
When the Earth is facing away from the Sun, a shadow appears, which is called the Earth shadow. The earth's shadow is divided into two parts: the umbra and the penumbra. The umbra refers to the area that is not directly exposed to sunlight, while the penumbra is only partially exposed to direct sunlight. During its orbit around the Earth, the moon sometimes enters the Earth's shadow, which causes a lunar eclipse. A total lunar eclipse occurs when the entire moon enters the umbra; However, if only a part of it enters the umbra, only a partial lunar eclipse will occur. Both total lunar eclipses and partial lunar eclipses are umbra lunar eclipses.
Lunar eclipses can be classified into three types: partial lunar eclipses, total lunar eclipses and penumbral lunar eclipses. A partial lunar eclipse occurs when only part of the moon enters the Earth's umbra. The diameter of the Earth's umbra is still 2.5 times that of the Moon. So when the Earth and the Moon are roughly in a straight line, the moon will completely enter the Earth's umbra, resulting in a total lunar eclipse. If the moon is always partially covered by the Earth's umbra, that is, only part of the Earth's umbra, a partial lunar eclipse will occur. There will be no annular lunar eclipse on the moon. Because the volume of the Moon is smaller than that of the Earth, the phenomenon of a lunar annular eclipse does not occur within the Earth's umbra. The number of lunar eclipses occurring each year is generally two, with up to three, and sometimes none at all. Because under normal circumstances, the moon either passes above the Earth's umbra or departs below it, rarely passing through or partially passing through the Earth's umbra, lunar eclipses generally do not occur. According to observational data statistics, the percentages of penumbral lunar eclipses, partial lunar eclipses and total lunar eclipses occurring in the middle of each century are approximately 36.60%, 34.46% and 28.94% respectively.
The penumbral eclipse begins after a total lunar eclipse: The moon has just come into contact with the penumbra, and at this time, it is not detectable by the naked eye. The process of a formal lunar eclipse is divided into five stages: the initial phase, the completion of the eclipse, the maximum eclipse, the emergence of light, and the recovery of the full moon.
The penumbral eclipse begins when the moon just comes into contact with the penumbra. At this time, the luminosity of the moon's surface slightly decreases, but it is difficult to detect with the naked eye.
The first eclipse (only partial lunar eclipse and total lunar eclipse) : It marks the beginning of a lunar eclipse. The moon gradually enters the Earth's shadow from its eastern edge, and the moon and the Earth's umbra are slightly circumscribed.
A total lunar eclipse (only a total lunar eclipse) : The moon enters the Earth's umbra and is in a secondary internal tangent with it. The moon has just entered the Earth's umbra completely.
Maximum eclipse: When the full moon is close to the Earth's umbra, the surface of the moon appears copper-red or dark red around this time. The reason is that when sunlight passes through the Earth's atmosphere, it undergoes refraction, causing the light to be deflected inward. However, the degree of deflection varies for each type of light (dispersion). Red light is more deflected, approaching the Earth's shadow and being reflected on the moon. In addition, due to the different contents and positions of dust and clouds in the atmosphere, the degree of light deflection varies. Therefore, during a total lunar eclipse, the moon appears dark red, copper-red, or orange. By the same token, due to the refraction of the atmosphere, the rising sun and the setting sun are not white, but appear orange or red depending on the height and the degree of atmospheric refraction.
Luminescence (only total lunar eclipse) : The moon moves within the Earth's umbra and makes a second internal tangent with the Earth's umbra. The total eclipse phase comes to an end when the eastern edge of the moon is tangent to the eastern edge of the Earth's umbra.
Full moon (only partial lunar eclipses and total lunar eclipses) : The moon gradually moves away from the Earth's umbra and is tangent to it for the second time. When the western edge of the moon is tangent to the eastern edge of the Earth's umbra, the entire lunar eclipse comes to an end. The extent to which the moon is eclipsed is called "eclipse magnitude", which is equal to the ratio of the distance from the edge of the moon's moon into the Earth's umbra at the maximum eclipse to the moon's apparent longitude.
Penumbral eclipse end: The moon leaves the penumbra, marking the official conclusion of the entire lunar eclipse process. A partial lunar eclipse does not have the process of eclipse completion or luminescence. The maximum eclipse only indicates the moment when the Earth's shadow is approaching.
The magnitude of a lunar eclipse is indicated by the magnitude of the eclipse. The magnitude of the eclipse is equal to the ratio of the apparent diameter of the Moon that enters the umbra at the maximum eclipse to the apparent diameter of the moon. When the maximum eclipse occurs, if the moon is exactly tangent to the umbra, the magnitude of the eclipse is equal to 1. At the maximum eclipse, if the moon goes deeper into the umbra, the magnitude of the eclipse is indicated by a number greater than 1. The magnitude of a total lunar eclipse is greater than or equal to 1. The food content of picky eaters is all less than 1. The magnitude of a penumbral lunar eclipse is expressed as the ratio of the part of the moon's diameter that enters the penumbra to the apparent diameter of the Moon. A penumbral lunar eclipse can only be detected by the naked eye when its magnitude exceeds 0.7.