For good #astronomy lectures aimed at general audiences, look at The Silicon Valley Astronomy Lecture Series; see link to YouTube via
https://foothill.edu/astronomy/
(There I first attended a lecture on discovering exoplanets by Dr Geoff Marcy in 1996, which predated the series by a few years.)
For me, one thing that makes a lecture good is hearing what a speaker finds interesting about a subject.
Chirp! is a social network. It runs on GNU social, version 2.0.1-beta0, available under the GNU Affero General Public License.
All Chirp! content and data are available under the Creative Commons Attribution 3.0 license.