Astronauta vs. cosmonauta
The Italian words 'astronauta' and 'cosmonauta' both refer to space travelers, but they have subtle differences in usage and origin.
Astronauta
'Astronauta' is the most common Italian term for a person who travels in space. It is derived from the English word 'astronaut' and is used generally for space travelers from Western countries.
Samantha Cristoforetti è la prima donna astronauta italiana.
(Samantha Cristoforetti is the first Italian female astronaut.)
Gli astronauti della NASA si addestrano per anni prima di andare nello spazio.
(NASA astronauts train for years before going to space.)
Cosmonauta
'Cosmonauta' is less commonly used in Italian and typically refers specifically to Russian or Soviet space travelers. It comes from the Russian term 'kosmonavt'.
Yuri Gagarin è stato il primo cosmonauta a orbitare intorno alla Terra.
(Yuri Gagarin was the first cosmonaut to orbit the Earth.)
I cosmonauti russi indossano tute spaziali diverse da quelle degli astronauti americani.
(Russian cosmonauts wear different spacesuits from American astronauts.)
Summary
While 'astronauta' is the general term for space travelers in Italian, 'cosmonauta' is typically used for Russian or Soviet space explorers. Both words describe people who travel in space, but their usage differs based on the nationality or space program of the individual being referred to.