Above us only sky...

When I watch the stars and satellites I often recall something once said by an outdoor educator, Margaret McMillan in 1925, 'The best classroom and richest cupboard is roofed only by sky'. So much knowledge has been gained from space travel and from data from satellites but I gather the increasing number of them has started to hinder land based telescopes. 

This evening I captured the ISS going over again plus two others I can't identify. 

The numbers are staggering but hard to confirm*. The UK has about 522 operational satellites, Russia over 1500 and the US around 4500, that excludes Starlink (SpaceX) who has at least 6111 and plan to get 42000 up there! 

*All these figures have a wide range of error, ie Russia is shown to have between 170 and 1500 depending who you ask...