It is known that one of the supposed criteria for the detection of extraterrestrial civilizations is the so-called cosmic miracle, which cannot be explained by natural causes. What can serve as a cosmic miracle for an alien Earth observer?
The earth radiates the same power as the sun in the range of meter radio waves. The radiation of the Earth in this range exceeds the radio emission of Venus or Mercury by millions of times.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.