- A planetary nebula is a type of emission nebula consisting of an expanding, glowing shell of ionized gas ejected from red giant stars late in their lives.
- A Portrait of Tenochtitlan (thomaskole.nl)
The year is 1518. Mexico-Tenochtitlan, once an unassuming settlement in the middle of Lake Texcoco, now a bustling metropolis. It is the capital of an empire ruling over, and receiving tribute from, more than 5 million people. Tenochtitlan is home to 200.000 farmers, artisans, merchants, soldiers, priests and aristocrats. At this time, it is one of the largest cities in the world.