Aristarchus timed how long the Moon took to travel through Earth's shadow and compared this with the time required for the Moon to move a distance equal to its diameter (this could be done by timing how long a bright star in obscured by the Moon).
(Aristarchus; timed; how long the Moon took to travel through Earth's shadow and compared this with the time) (the Moon; to move; a distance equal to its diameter) (this; could be done; ) (the Moon; to travel; through Earth's shadow) (the Moon; compared; this) (the time; required; for the Moon to move a distance equal to its diameter)
Aristarchus the Moon this the Moon the Moon the time
timed to move could be done to travel compared required
how long the Moon took to travel through Earth's shadow and compared this with the time
a distance equal to its diameter
through Earth's shadow
this
for the Moon to move a distance equal to its diameter