Question

What is the meaning of the Greek word ‘Planetai’ that is used for planet?

Answer 1

Hint: Characteristics of light is basically referred to as the information which can be used to describe light. We can list some characteristics of light by describing its speed, its nature, its behavior in different mediums, various phenomena it undergoes, its range along the electromagnetic spectrum. Hence from the above characteristic we will describe light.

Complete step-by-step solution:
The ancient Greek astronomers coined the term asteres Planetai i.e. wandering stars for star like objects which apparently move over the sky over the course of the year. Now it must be clear as to why we refer to planets as Planetai as these celestial bodies move over the sky as per our reference. Over the centuries different heavenly bodies from the sun to satellites and meteors.

Additional information:
In the modern world, there are two primary conceptions of a planet. The first is that if an astronomical body orbits the sun and the relationship to the other bodies is comparable to those of classical planets. Secondly the planet should be round or should have a planetary geology. These are categorized as the orbital definition and geophysical definition.

Note:The five celestial bodies now called the planets i.e. Mercury, Venus, Mars Jupiter and Saturn were visible to the ancient Greeks via naked eye. In our solar system we have the definition of the planet coined by (IAU) International Astronomical union. According to the definition a planet is a body that orbits the sun, it is massive enough for its own gravity to make it round and has cleared its neighborhood of smaller objects obstructing its orbit.