Why does the position of the constellation orion appear to change throughout the year, and why can't orion be seen in the summer sky?

Earth travels round the Sun in Twelve months, the stars that are visible at midnight each night shift slowly by about 1 degree every 24 hours so that a complete circle round the sky is completed once a year. 

Because earth revolves around the sun and that causes the position to seemingly change as the Earth moves.

Further Explanation:

Orion is situated on the celestial part of the equator and it is visible from all over the world. Orion is the most recognizable constellations in the night sky and The name Orion comes after the Greek hunter, Orion.  The brightest star of Orion is blue-white Rigel and Red Betelgeuse. Orion is located on the celestial equator but it won't remain there forever because it changes its position along with the axis of the earth.  

According to the scientists, In further future, the stars of Orion will start moving away from each other and that will be due to proper motion and the brightest stars of Orion lie on the large distance from the Earth at the astronomical scale but Orion will still be very much visible even after the most of the constellations will fade away. The position of Orion changes from time to time and this phenomenon occurs because the earth revolves around the sun.  

Learn More:

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Answer Details:

Grade: High School

Chapter: Orion

Subject: Geography

Keywords: Orion, Stars, Astronomical, Axis, Scientists, Constellation, Brightest star, Rigel, Red Betelgeuse, Equator.

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