The Tropics of Capricorn and Cancer were called for the two locations in the globe when the sun may be directly above. These were key demarcation lines for ancient travelers who relied on the sky to guide them. Today, these locations are important for sailors as they approach distant shores.
The Capricorn tropic is located in the remote region of Central Australia. It marks the end of the Australian continent. South of this line lie tropical climates with year-round heat and no real seasons. North of this line are found temperate climates with distinct summer and winter months.
The Cancer tropic lies near the city of San Cristobal de la Habana in Cuba. This is the point at which you turn south toward the warmer climates of Colombia and Venezuela. North of this line are found cold climates with short summers and long winters.
These are the only two places where you will find tropical climates on Earth. Everything else is either hot or cold with areas of both.
Modern scientists have also discovered that there are actually three more tropical regions of the planet. They are:
1. The Gulf of Mexico between Texas and Florida. This is because of its constant temperature due to its proximity to a body of water (the ocean).
2. The Amazon River basin.
The Tropic of Cancer is significant in Earth's geography because it not only marks the northernmost point where the sun's rays are directly overhead, but it also marks the northern boundary of the tropics, which is the region that extends from the equator north to the Tropic of Cancer and south to the Tropic of Capricorn. The word "tropical" comes from Latin tropicalis, meaning "of or pertaining to a region near the equator".
The Tropic of Cancer has been important for astrologers because it represents the northern limit of the zodiac, which begins with Gemini on the opposite side of the planet. Thus, animals born under the sign of Cancer are limited to the Northern Hemisphere, while those born under the sign of Gemini can be found living in both the Northern and Southern Hemispheres.
In addition to being the northern limit of the zodiac, the Tropic of Cancer is important in astronomy because it is the line beyond which the earth's atmosphere blocks out most of the sun's radiation. On either side of this line are areas in which the sun causes plants to grow quickly and heavily during the summer months, but without any winter chill. This is why astronomers use the term "tropical zone" to describe the area between the Tropic of Cancer and the Tropic of Capricorn.
The "tropics" are defined as the area limited on the north by the Tropic of Cancer and on the south by the Tropic of Capricorn. Because the sun is permanently high in the sky, there are no seasons in this location. The temperature remains constant all year round at about 72 degrees Fahrenheit.
The term "tropics" comes from the Latin word for tropic, which means "turning point". This refers to the fact that the points where the equator crosses the lines of latitude circle around the earth are called "tropics".
The celestial equator is the name given to the line on Earth's surface that forms a great circle with North at its center. It passes through the centers of gravity of the planet, but not directly over any major city because of the curvature of the Earth. Cities do affect the path of the celestial equator through space, however; areas near the equator experience more tropical storms and earthquakes than farther from it.
The celestial equator divides the Earth into two equal parts: the northern hemisphere, which includes most of Canada, the United States, and Europe; and the southern hemisphere, which includes most of Australia, South America, and Africa.
The celestial equator runs through the center of our planet, from the North Pole to the South Pole.
Capricorn's Tropic is located 23.4 degrees south of the Equator. The Tropics refer to the region between the Tropics of Cancer and Capricorn. They are identified by the fact that the sun is over the equator for 12 months out of the year, regardless of the date or time of year.
The term "Tropics" comes from the Latin word meaning "turning point". The Tropics are considered the turning point between the cold of the Arctic and the heat of the Gulf of Mexico. All seasons are found in the Tropics, but they are most likely to be affected by extreme temperatures during the annual cycle of tropical storms and hurricanes.
The Trenches, as the Tropics are called by sailors, play an important role in ocean navigation. Without them, ships would run into problems finding enough wind to move themselves across the ocean floor. Deep-sea vessels must travel through these trenches to escape local weather conditions and find more favorable currents elsewhere.
It used to be thought that humans could not live without air conditioning, but this misconception was given some credit when researchers discovered that astronauts on space missions do not suffer from heat exhaustion because their bodies are able to cool itself through natural processes outside of Earth's atmosphere.
The Tropics are located south of the Tropic of Cancer and north of the Tropic of Capricorn. Its seasons are defined by a mix of trade winds that draw water from the oceans and generate seasonal rains known as monsoons on the eastern shores.
The sun pointed in the direction of the Cancer constellation at the June solstice or summer solstice, giving the new latitude line the name "Tropic of Cancer." However, it should be noted that this name was given to the sun almost 2,000 years ago, and the sun is no longer situated in the Cancer constellation.
The Tropic of Cancer was called because the sun was in the Cancer constellation on the June solstice at the time of its designation. Similarly, the Tropic of Capricorn was called because the sun was in Capricorn on the December solstice. Today, these terms have no special meaning; they are simply labels for divisions of the earth's surface that experience a constant daily temperature of about 32 degrees Celsius (90 degrees Fahrenheit).
The names "tropic of Cancer" and "tropic of Capricorn" came to be used by astronomers and geographers to describe these regions of the world map. They are not actual constellations in the night sky, but rather arbitrary lines on a globe used to divide the earth into two equal-size portions: the northern hemisphere, which includes most of North America and Europe; and the southern hemisphere, which includes most of Africa and Australia.
These names were first used by Claudius Ptolemy in his Geography. He used the words "tropics of Cancer and Capricorn" instead of just "tropics" because it was before the days of satellites and airplane travel. Back then, people knew the earth as a circle, so they needed more than one word to describe all the way around it.