“Draw a pony star gazing / Draw a pony being eclipsed.”
 
Celestia and Luna, many years ago, about a year after they were rescued from their captivity and came to live in the house of Bolero, their foster father. Eleven-year-old Luna was still very quiet and reserved, but nothing caused her to open up like the night sky. Celestia found every clear, quiet evening that they could go out into the estate and admire the stars until Luna fell asleep in her sister’s arms. It brought them both a measure of peace. But Celestia often teared up, thinking about their mother and father, who had introduced them to the beauty of the night sky…
 
A bit of Air Ponyville lore. And hey, Luna is covering most of Celestia, so it’s about a 75% eclipse, right?