A very good morning to one and all present here. Today, I’ll be giving a short speech on the topic of ‘Planets’.
Google and Wikipedia offer two slightly varied definitions for the term ‘planet’, both of which are invariably correct.
Google states that a planet is “a celestial body moving in an elliptical orbit round a star.” Wikipedia, meanwhile states that it is “a large, rounded astronomical body that is neither a star nor its remnant.”
What both these reveal is that planets are large, celestial objects which move around a star i.e, the sun. In addition, NASA also states that a planet “has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a hydrostatic equilibrium (nearly round) shape”, and “has cleared the neighbourhood around its orbit.”
In the Universe, there are ~1025 planets that are said to orbit stars! In the Solar System, however, we have 8 planets that we all know of- Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.