I think you mean the moons of Saturn and Jupiter, as those planets are visible to the naked eye and well known to many people.Well, they are rarely discussed even though they are known for their amazing knowledge of the Sirius B companion star and Saturn and Jupiter before any European discovered it. I think they deserve more attention than the Egyptians for a change as some white astronomers and anthropologists are still amazed as to how they knew about these three things before them.
I suspect that rather than thinking the Dogon were Egyptian, that they were influenced by Egyptians, or if earlier than them, by the Saharans, whose society stretched east-west for 3000 miles. They were associated with astronomical monuments such as that discovered at Nabta, a small henge 1000 years older than "Stonehenge" in England.
There are indications of Saharan origin for some of Egyptian culture. The Saharans were the people ancestral to modern West Africans, as they migrated south into West Africa when the Sahara dried.
The Saharan, called African Aquatic by anthropologists, is just being uncovered. Little is yet known, but what is known is amazing and indicates complex and advanced culture in Africa before Egypt (in addition to those of Nubia and Ethiopia).