Ancient Greeks know some of aspects of the universe better than a vast majority of us nowadays. 😥
More than 2000 years ago, the Greeks knew that the Moon shines by reflection of sunlight, and lunar eclipse is caused by the shadow of the Earth on the Moon. From the curvature of the shadow during lunar eclipse, Aristarchus determined that the Moon is 0.35 of the size of the Earth (Kwok, S. 2017, "Our Place in the Universe", chapter 8, Springer). This is illustrated in the lunar eclipse picture taken last night.
