Re: Solar vs RTG...
From what I've seen, the smallest one is currently around 2kg, but the ones big enough to power Perseverance are more like 40kg.
Ingenuity also weighs about 2kg in total.
The problem is how much power RPGs can supply in one go. They're fine for keeping instruments alive or trundling gently across the landscape with a steady power requirement, but spinning propellers at high rpm in a thin atmosphere to get lift demands more.
Of course, future iterations of Ingenuity might contain more instruments and be much bigger, so would be heavier pro rata and require even more power to get lift.
It'll be interesting to see how it all develops.
Biting the hand that feeds IT
