Me thinks interstellar dust blocks radio transmissions, particularly metallic dust.
I believe you to be correct. There undoubtedly are countless objects or particles and our knowledge is infinitely incomplete. If we still had a manned space program a good place to gain knowledge would be in our own or God’s solar system of which all of us are a part. Smokin’ Joe was correct ... Mars ... we should have been there, done that and gone on to the next task (imho). Most everything learned or discovered was during the race to the moon. To open up new avenues of learning and discovery one must reach for the stars. I truly believe this. No wonder zer0 shut most of the learning and discovery down. zer0 is quite successful in creating a return of zer0.