Which effect limited astrolabe accuracy when observing planets near the horizon?

💡 Explanation

When observing planets near the horizon, atmospheric refraction occurs because the density gradient bends light, distorting elevation angles and causing positional errors. Therefore, atmospheric refraction limits accuracy, rather than parallax, orbit shapes, or thermal expansion which have distinct underlying causes and magnitude.

• Which benefit did pre-Columbian terracing provide specifically in regions with significant seasonal rainfall?
• Which outcome resulted from intensive maize cultivation in the pre-Columbian Americas using slash-and-burn techniques?
• Which design risk increased when early ironclad warships used thicker armor plating?
• Which effect contributes to structural instability when timber framing joints experience repeated wetting and drying cycles?
• Which outcome resulted when pre-Columbian agriculturalists intensively cultivated maize using chinampas?
• Within chinampa agriculture, which limit arises if excessive nutrient-rich sediment accumulates on the plots?