Don't know about the leopard and model x, but at least in the case of OpenAI luna > Terra > Sol > Astra is a pretty obvious size progression.
But I come from a latin language background, so maybe I'm a bit biased there.
Luna = Moon
Terra = Earth
Sol = Sun
Astra = GalaxyGood God, what has happened to people here? You literally wrote that Luna is greater than Terra, Terra is greater than Sol and so on.
At the risk of taking a geocentric position, my gut feel is Terra -> Luna -> Sol -> Astra. Sorting algorithm is distance from observer.
Size wise Astra is not categorically bigger than Sol, both in absolute terms and the observed size.