What is a sextant used for?

A sextant is primarily used for navigational purposes by sailors, particularly during the age of exploration and beyond. It is an instrument designed to measure the angle between two visible objects, such as the horizon and a celestial body (like the sun or stars). This measurement allows navigators to determine their latitude and longitude at sea, which is crucial for accurately plotting a course and ensuring safe travel across oceans.

In the context of Mesoamerican history and European exploration, the sextant played a vital role as it enabled European sailors to navigate unfamiliar waters. As they explored and colonized parts of the Americas, the ability to navigate effectively became essential for trade, exploration, and military endeavors.

The other choices do not align with the primary function of a sextant. Measuring temperature is not a function associated with a sextant; instead, it pertains to thermometers. Calculating time involves different instruments, such as clocks or chronometers, which are not related to the celestial navigation functions of a sextant. Harvesting crops is entirely unrelated, as sextants have no agricultural application. Thus, the choice related to navigational purposes for European sailors is indeed the most accurate regarding the use of a sextant.