Rasid Tugral won fans in the social media stratosphere for his mesmerizing photos of the night sky over his Turkish homeland. He shared images – such as one of a juniper tree against a glistening Milky Way – on a National Geographic website. He entered a prestigious graduate program in astrophysics in Finland. Smart, handsome, adventurous and outgoing, he seemed destined for a career studying the skies.

But Tugral yearned for something more. An observant Muslim raised in a conservative household, he became drawn to jihadi websites while in college. Tugral took their radical interpretation of Islam to heart. Early in 2015, he slipped away from his family and a comfortable life, joining Islamic State (IS) jihadis fighting inside Syria.

By last August, Tugral was dead, an apparent casualty while fighting for IS against Kurdish forces. He was 27.

Thousands of young Muslims, lured by IS ideology and propaganda, have traveled to join and fight for the terrorists' self-proclaimed caliphate in Iraq and Syria. Like Tugral, many abandoned lives of privilege and potential. His story stands out, however, because of the extensive written and photographic record he left documenting his transformation over more than a decade.