Two days ago: https://news.ycombinator.com/item?id=41661673
The one subtitled "A glyph of a human and animal interacting" looks like the human is holding a long spear that didn't get outlined
What does Erich von Daniken have to say about this revelation?
Aliens
Unrelated: Cowboy Bebop episode about rogue satellite AI carving these into the Earth to amuse itself