Category Archives: Solar System

Armillary sphere

An armillary sphere (variations are known as spherical astrolabe, armilla, or armil) is a model of the celestial sphere. read on…

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Sidereal time

As the Earth rotates from west to east around its axis once every 23 hours 56 minutes, the celestial sphere and all objects on it appear to rotate from east to west around the celestial poles in the same time. … Continue reading

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Celestial sphere

In astronomy and navigation, the celestial sphere is an imaginary rotating sphere of “gigantic radius”, concentric and coaxial with the Earth. All objects in the sky can be thought of as lying upon the sphere. Projected from their corresponding geographic … Continue reading

Posted in Class Notes, Geography Practicals/Lab and Statistical Techniques, Solar System | 6 Comments

Van Allen radiation belt

The Van Allen radiation belt is a torus of energetic charged particles (plasma) around Earth, held in place by Earth’s magnetic field. Earth’s geomagnetic field is not uniformly distributed around its surface. On the sun side, it is compressed because of … Continue reading

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