The horse latitudes refer to the subtropical regions of the Earth, known for calm winds and little precipitation. These regions are typically located between 30 and 35 degrees north and south of the equator. They are characterized by high atmospheric pressure and are associated with the subtropical high-pressure belts, also known as the subtropical anticyclones.

The term "horse latitudes" originated from the historical practice of sailors throwing horses overboard when they ran out of drinking water during long voyages. The lack of wind in these regions often left ships stranded for extended periods, leading to a shortage of fresh water and forcing sailors to make difficult decisions.

Below are some key points to explain the answer in detail:

1. Subtropical Regions: The horse latitudes are found in the subtropical regions, which are located between the tropical and temperate zones of the Earth.

2. Calm Winds: These regions are known for their calm winds, where the prevailing winds are often weak or nonexistent. This lack of wind is due to the descending air associated with the subtropical high-pressure systems.

3. Little Precipitation: The horse latitudes are characterized by a lack of precipitation. The descending air masses in these regions inhibit the formation of clouds and precipitation, resulting in arid or semi-arid conditions.

4. Subtropical High-Pressure Belts: The horse latitudes are part of the subtropical high-pressure belts, which are regions of high atmospheric pressure. These high-pressure systems are caused by the sinking air from the upper atmosphere.

5. Historical Significance: The term "horse latitudes" has historical significance in the context of sailing. Sailors in the past would sometimes find themselves stranded in these regions due to the lack of winds, leading to water shortages and desperate measures such as throwing horses overboard.

In conclusion, the horse latitudes are subtropical regions known for their calm winds and little precipitation. These regions are characterized by high atmospheric pressure and are part of the subtropical high-pressure belts. The historical significance of the term adds to the understanding of the challenges faced by sailors in these regions.