I have a physics project that has to be made of this man

Aristarchus (Greek: Ἀρίσταρχος; 310 BC - ca. 230 BC)
I'm a little lost that what has he actually achieved?only thing I know that he was a Greek astronomer. can u guys find something?

Aristarchus (Greek: Ἀρίσταρχος; 310 BC - ca. 230 BC)
I'm a little lost that what has he actually achieved?only thing I know that he was a Greek astronomer. can u guys find something?