We have a lot of astronomy lectures - worth using search if there is something specific you're looking for.
General
Cosmic Concepts series Katherine Blundell
Why Society Needs Astronomy and Cosmology Roberto Trotta
The Nature of Reality series Roberto Trotta
In the Beginning Joe Silk (the early Universe, the Big Bang etc)
How Special is Our Universe? Joe Silk
Are We Alone in the Universe? Joe Silk
How Common is Life in the Universe? Joe Silk
Dark Matters Joe Silk
Elementary Particles and their Interactions Joe Silk
Ultra-Compact Objects: Astronomy with Gravitational Waves Joe Silk
The High-Energy Universe Joe Silk
Issues
Existential Risks in the Solar System Joe Silk
The Moon
50 years of Lunar Exploration Joe Silk
Great Astronomers/ physicists
Caroline Herschel Discoverer of Comets Sheila Kanani
What has Einstein ever done for you? Roberto Trotta