In the northern sky in December is a beautiful cluster of stars known as the Pleiades, or the “seven sisters.” Look carefully and you will probably count six stars. So why do we say there are seven of them?
![](https://scx1.b-cdn.net/csz/news/tmb/2020/theworldsold.jpg)
Source:
https://phys.org/news/2020-12-world-oldest-story-astronomers-global.html