Norse mythology number 9 ?

That is doubtful. The Norse were great at navigating by the stars, but there is next to no evidence that they excelled in astronomy beyond that, as in cultures where religious calenders and events were carefully calculated by the spinning of the earth and the revolution of the planet and how celestial objects seemed to "move" by this. Probably the Norse made a more mundane observation and placed special significance on the number 3. Triads hold a fascination for mythologies, and there are many theories as to why this commonly reoccurs, but I find it uncanny that many physio-chemical mathematical relations work in threes. The Norse share this reverence for the number 3, and I imagine the number 9 could have become significant as it is the divine number multiplied by itself. All we can do is speculate, though; in Irish mythology, the number 3 was also very significant, but so was seven and four. Besides, there are bits and pieces of the Norse mythology other than the Edda where some of the "9 elements" were actually a different number - the Edda cannot be wholely relied upon because it was written by one man who could have altered numbers and dynamics to the pagan myths for his own purposes or convenience.

I believe that in the past we were visited by extraterrestrials and they handed down their knowledge to the ancients. My reasoning: The great pyramid of Giza is the exact center of all the landmass on earth. The pyramid of the moon in Tenochtitlan has the same perimeter as the great pyramid of Giza. Some Indian tribes (though its extremely hard to get the information from them) claim that extraterrestrials are the source of their knowledge. Sights such as stone-henge around the world, were significantly advanced for their time. And I could go on for a long time.... But back on topic, I believe that they certainly had knowledge of the stars and universe and that's how the numeral 9 became so significant in the Prose Edda and other Nordic tales.

I believe that in the past we were visited by extraterrestrials and they handed down their knowledge to the ancients. My reasoning: The great pyramid of Giza is the exact center of all the landmass on earth. The pyramid of the moon in Tenochtitlan has the same perimeter as the great pyramid of Giza. Some Indian tribes (though its extremely hard to get the information from them) claim that extraterrestrials are the source of their knowledge. Sights such as stone-henge around the world, were significantly advanced for their time. And I could go on for a long time.... But back on topic, I believe that they certainly had knowledge of the stars and universe and that's how the numeral 9 became so significant in the Prose Edda and other Nordic tales.