Summary
                        
        
                            Without the protection by the Earth’s atmosphere, there would be no life on Earth – for most astronomical measurements, however, the atmosphere is an obstacle. Observers thus started early to move their instrument as high above the perturbing atmospheric layers as...
                    
    
        
                                 
                    More information & hyperlinks
                        
        | Web resources: | https://esbo-ds.irs.uni-stuttgart.de |