You act like they didn't invest time and energy to create interesting content (compilation, editing, professional voiceover, community building, etc)? This isn't public domain pictures reuploaded on a blog spam website with zero effort.
Not to mention spreading science wider through promotion is a valuable service to society. Not everyone browses nasa.gov sites. Nor does raw content always hit frontpage of HN.
Not to mention spreading science wider through promotion is a valuable service to society. Not everyone browses nasa.gov sites. Nor does raw content always hit frontpage of HN.