2 moments

1. Earliest exactly dated astronomical observation

   0127-03-26 · Alexandria, Egypt

   

   Ptolemy made his earliest exactly datable astronomical observation from Alexandria, beginning the securely documented span of his observational work there. Coordinates represent central ancient/modern Alexandria; the source does not identify a more precise observing site.

2. Last exactly dated astronomical observation

   0141-02-02 · Alexandria, Egypt

   

   Ptolemy's last exactly datable recorded astronomical observation was made from Alexandria, marking the latest securely dated observation in this documented series. Coordinates represent central ancient/modern Alexandria; the source does not identify a more precise observing site.