What would you like to do?

Why did ancient civilizations only know about six planets?

already exists.

Would you like to merge this question into it?

already exists as an alternate of this question.

Would you like to make it the primary and merge this question into it?

exists and is an alternate of .

The ancients only knew about (5 planets + Earth) because to really see the other two you needed a telescope. The planets they knew were:
  1. Mercury
  2. Venus
  3. (Earth)
  4. Mars
  5. Jupiter
  6. Saturn
All these are easily visible to the naked eye and of cause they can be seen to move against the background of the stars (except the Earth because we are on that)
It was in 1718 (290 years ago) that Uranus the 7th planet was discovered by William Herschel using a telescope. Although it is visible to the naked eye like the other six, it was never recognized as a planet by ancient observers due to its dimness and slow orbit. The 8th planet Neptune was found by mathematical prediction rather than regular observation. Unexpected changes in the orbit of Uranus led astronomers to deduce the gravitational perturbation of an unknown planet was the cause and they predicted where to look to find it.
3 people found this useful
Thanks for the feedback!

Why is ancient Rome a significant ancient civilization?

This can be seen in the  legacies of the Romans in religion, the alphabet, language, the  calendar, law, architecture and literature.   Christianity developed  from a r

How did ancient astronomers know the difference between planets and stars?

      Ancient astronomers can tell the difference the same way you can tell now - the planets move, while the stars stay in the same patterns. The word "planet" c

What planet is the only planet to rotate clockwise?

Venus and Uranus rotate in the opposite direction to all the other planets. So, in fact, there are two planets that rotate clockwise. Actually there are two. They are Uranus a

What six planets were known to the Ancient Greeks?

To the Greeks and Romans there were seven known planets, each presumed to be circling the Earth. They considered the moon a planet which makes seven. The moon, Mercury, Venus,

Which ancient civilization defeated the ancient Egyptian civilization?

A few Civilizations defeated the Egyptians, resulting in what are know as Intermediary periods. The Nubians, The Hyksos Kings (Isrealites), The Persian Empire all ruled in Egy

What planet did the ancient Greeks not know about?

The greek Aristotle writted a theorie of the universe based on what Greeks considered geometrical perfect bodies; 5 bodies, then 5 planets: Mercury, Venus, Mars, Jupiter, and

What where the ancient civilizations?

The Aztecs in South America, Mayans in Central America, Incans in Peru, Romans in Europe, Egyptians in northern Africa, Babylonians, Assyrians, Sumerians, and Persians in mode

What do you know about planets?

I know a lot! For example there are 8 planets and I believe 6 Plutaroids, there may be more. The Plutaroids that I know about a Pluto, Eris, Makemake, Ceres ( Not sure if spel

What planets were not known to ancient people?

Uranus was discovered by William Herschel on March 13, 1781     Neptune was discovered on September 23, 1846 by Johann Gottfried Galle and Heinrich Louis d'Arrest.