The seven continents

Asia alone covers about 44.6 million square kilometres, almost six times the area of Australia.

What counts as a continent

A continent is one of the very large masses of land on Earth. That sounds simple, but the land does not come with labels, and people have drawn the lines in different places. Depending on the convention, the number of continents runs from five to seven. The most common list, taught in many English-speaking countries and used in this course, has seven: Asia, Africa, North America, South America, Antarctica, Europe and Australia. Some countries teach Europe and Asia as one continent, Eurasia, and others treat North and South America as one, the Americas. Use both of those and the count falls to five.

The borders between continents are mostly agreements, not cliffs. North America is usually taken to include Greenland and the Caribbean islands and to end at the Isthmus of Panama. Europe ends in the east at the Ural Mountains and the Ural River, with the Caspian Sea at its southeast corner and the Caucasus Mountains, the Black Sea and the Mediterranean to the south. Africa meets Asia at the Isthmus of Suez, although the Sinai Peninsula, which lies east of it, is often counted with Egypt and so with Africa. Asia takes in all the islands of the Philippines, Malaysia and Indonesia, and the Pacific islands are often grouped with Australia under the name Oceania.

From largest to smallest

The World Factbook lists the land areas as follows: Asia about 44.6 million square kilometres, Africa 30.1 million, North America 24.5 million, South America 17.8 million, Antarctica 14.2 million, Europe 9.9 million and Australia 7.7 million. Add them up and you get about 148.8 million square kilometres, which is close to the 148.9 million the Factbook gives for all the land on Earth. That land is only 29.1 percent of the planet’s surface. The other 70.9 percent is water, which is the subject of the next unit.

Asia covers about 30 percent of all land, so the largest continent alone holds nearly a third of the dry surface. Africa is second, and it straddles the equator almost evenly, reaching from the Mediterranean to the Cape of Good Hope. Europe and Australia are the two smallest, and Europe is only about 1.3 times the size of Australia. The difference is that Australia is one country, while Europe holds more than 40.

Antarctica, the continent under ice

Antarctica is the fifth largest continent, bigger than both Europe and Australia. Of its 14.2 million square kilometres, about 13.9 million are covered by ice and only about 285,000 are bare rock. The Factbook calls it the coldest, windiest and driest continent, and also the highest on average, with a mean elevation of about 2,300 metres, because the ice sheet itself is so thick. No one lives there permanently. Scientists stay at research stations, and the population rises in summer and falls in winter.

A way to remember the order

The order by size is worth learning once, because many later facts hang on it. One way is to split it into pairs. Asia and Africa are the two giants. North and South America come next, in that order, north before south. Then come the three smaller ones: Antarctica, Europe and Australia, each smaller than the last. Try saying the list aloud while turning the globe above, and click one country on each continent except Antarctica as you name it.