Astronomer

천문학자

"Astronomers had found several other worlds like Pluto, so the IAU had the choice: call them all planets or downgrade.

Target Pluto: fastest spaceship set for epic encounter with our remotest planet

Nasa’s New Horizons spaceship has travelled billions of miles in nine years to answer astronomers’ questions about the tiny world

https://www.theguardian.com/science/2015/apr/11/pluto-new-horizons-spaceship-epic-encounter-planet#:~:text=%22Astronomers%20had%20found%20several%20other%20worlds%20like%20Pluto%2C%20so%20the%20IAU%20had%20the%20choice%3A%20call%20them%20all%20planets%20or%20downgrade.%20