I don't know how to do imperitives, but you watch the sky is: Caelum vides (you=singular). Caelum videtis (you=plural).
The latin word for observe is observare. Observer is the adjective.
Cael. The Latin word for sky is caelum, and the word for heaven is caeli
a stethoscope
observe carefully
Caelum.
He invented the telescope.
Because the earth is rotating.
Caelum.
Caelum.
observe the sky begin to blanch
Spectare: to watch, to look at, to observe. If you wish to tell someone to watch, use the imperative, which is specta.
Highest in the Sky.