Hello! This one is easy to describe and hard to implement. I would love if there was a mechanism that would:
1. Give hints or announce the player of an upcoming astronomical event, so the player has time to prepare an observation mission and experiments.
2. Allow the player/s (if multiplayer) to witness astronomical events in the game like:
--- eclipses
--- planetary alignment
--- meteor shower
--- asteroid / comet impact
--- huge volcanic eruptions
--- huge sun flares / solarstorms
--- huge vortex on gas giant (to send a probe falling into it)
--- huge geizer eruptions
--- object getting ripped apart by very strong gravity (like how the rings of Saturn we're formed)
--- comet passing through planetary rings
--- merging of two huge celestial bodies
--- rogue celestial body entering solar system (like an ice planet melting when passing too close to the sun)
--- merging stars
--- supernovae
--- neutron star polar beam scorching a planet
--- and I'm sure there are many more ideas
Example:
Oh and also flying over lava fields and giant waterfalls.