  Over the past decade, neutrino astronomy has emerged as a new window into the
extreme and hidden universe. Current generation experiments have detected
high-energy neutrinos of astrophysical origin and identified the first sources,
opening the field to discovery. Looking ahead, the authors of this Perspective
identify seven major open questions in neutrino astrophysics and particle
physics that could lead to transformative discoveries over the next 20 years.
These multi-disciplinary questions range from understanding the vicinity of a
black hole to unveiling the nature of neutrino mass, among other topics.
Additionally, we critically review the current experimental capabilities and
their limitations and, from there, discuss the interplay between different
proposed neutrino telescope technologies and analysis techniques. The authors
firmly believe that achieving the immense discovery potential over the next two
decades demands a model of global partnership and complementary specialized
detectors. This collaborative neutrino telescope network will pave the way for
a thriving multi-messenger era, transforming our understanding of neutrino
physics, astrophysics, and the extreme universe. \end{abstract}
