Piotr Kosek

Piotr Kosek (; born 1986) is a Polish educator and entertainer, publishing popular science educational videos about astronomy and space exploration, on his YouTube channel, titled Astrofaza (; from Latin astrum 'star', and Polish faza 'craving'). He also streams video games. As of October 2025, it has 595,000 subscribers, being the most popular Polish-language space-related YouTube channel.

Biography Piotr Kosek was born in 1986, and grew up in Płock, Poland. He has a degree in English studies. As of October 2025, it had 595,000 subscribers, being the most popular Polish-language space-related YouTube channel. Kosek cooperates with the Nicolaus Copernicus University in Toruń, and its Institute of Astronomy. In 2017, he was also a guest in an episode of the TVP educational television series Astronarium.

In 2017, he published 37-minute-long educational film about the black holes, titled Black Holes: Masters of Time and Space, which was awarded with a Grand Video Award in the popular science category. He was also nominated to awards Tech Awards 2017, Popularyzator Nauki 2018, and Grand Video Awards 2022.

A book written by him, titled Astrofaza – jak skończy się ludzkość? (Astrofaza: How Will the Humanity End?), was released in 2023 by Altenberg publishing house. It combines elements of novel and popular science education formats, presenting theories about the potential scenarios of the human extinction.