This is the 13605th most frequent Polish word.
planetą
"Planetą" in English means "planet" (instrumental singular form in Polish).
The word 'planetą' here is used in the instrumental case to describe Earth as being characterized by its nature as a planet full of life.
W Układzie Słonecznym Ziemia jest znana jako planetą pełną życia.
In the Solar System, Earth is known as a planet full of life.
In this sentence, 'planetą' is used in the instrumental case to identify the nature of the celestial object in relation to the discovery.
Astronomowie odkryli nową planetą poza naszym układem.
Astronomers discovered a new planet outside our system.
Here, 'planetą' is used in the instrumental case to denote fascination with each individual planet as objects of interest.