Water covers most of Earth! About 71% of Earth's surface is water. That is why astronauts call Earth the "Blue Planet." The water is mostly in five big oceans: the Pacific Ocean, Atlantic Ocean, Indian Ocean, Arctic Ocean, and Southern Ocean. The land is divided into seven continents. Even though land seems big to us, most of Earth is actually water!

The Pacific Ocean is the largest ocean! It covers about 63 million square miles – that is bigger than all the land on Earth put together! The Pacific Ocean is so big that you could fit all the continents inside it. It got its name from the word "peaceful" because early explorer Ferdinand Magellan thought it looked calm. The deepest part of any ocean is in the Pacific – the Mariana Trench is almost 7 miles deep!

Asia is the largest continent! It covers about 17.2 million square miles – that is almost one-third of all the land on Earth. Asia is home to China, India, Japan, Russia (part of it), and many other countries. The highest mountain in the world (Mount Everest) is in Asia. The most populated cities in the world are in Asia. Asia is so big that it touches three oceans: the Pacific, Indian, and Arctic Oceans.

A lake is a body of water surrounded by land! Most lakes are fresh water, but some lakes (like the Great Salt Lake in Utah) are salty. Lakes are different from rivers because the water does not flow in one direction. The largest lake in the world is the Caspian Sea – even though it is called a "sea," it is actually a lake because it is surrounded by land. It is salty, but it is still a lake. Canada has more lakes than any other country – over 2 million lakes!

The Nile River is the longest river in the world! It flows north through 11 countries in Africa before emptying into the Mediterranean Sea. The Amazon River is the second longest, but it carries more water than the Nile. Rivers have been very important to people throughout history – many ancient cities were built along rivers because they provided water and a way to travel. The longest river in North America is the Missouri River.

Mount Everest is the tallest mountain in the world! It is in the Himalayan mountain range, on the border between Nepal and China (Tibet). People called climbers try to reach the top, but it is very dangerous because of the cold, wind, and low oxygen. The first people to reach the top were Sir Edmund Hillary (from New Zealand) and Tenzing Norgay (from Nepal) in 1953. There are mountains on other planets too – the tallest mountain in our solar system is Olympus Mons on Mars, which is almost three times taller than Mount Everest!

An island is land surrounded by water! The largest island in the world is Greenland. Islands can be found in oceans, seas, lakes, and rivers. Some islands are connected to other islands in groups called archipelagos – like Hawaii, the Philippines, and Indonesia. Indonesia is a country made of over 17,000 islands! Some islands are uninhabited (no people live there), and some have big cities like Manhattan Island in New York City.

The Sahara Desert is the largest hot desert in the world! It covers about 3.6 million square miles across North Africa. The Sahara has sand dunes, rocky plateaus, and even mountains. Temperatures can be over 120°F (49°C) during the day and below freezing at night. Despite the harsh conditions, people (like the Berber and Tuareg people) and animals (like fennec foxes and addax antelopes) live in the Sahara. The largest desert overall is Antarctica (a cold desert) – it gets almost no rain or snow, just ice.

The Amazon Rainforest is the largest rainforest in the world! It covers about 40% of South America, mostly in Brazil. The Amazon has more kinds of plants and animals than anywhere else on Earth. One out of every ten species on Earth lives in the Amazon Rainforest! It is called "the lungs of the Earth" because it produces about 20% of the world's oxygen. The second largest rainforest is the Congo Rainforest in Africa.

The answer is ocean! Oceans are the largest bodies of water on Earth. They cover 71% of Earth's surface and contain 97% of Earth's water. The other 3% is fresh water in lakes, rivers, and glaciers. You have learned so much about the land and water features of our amazing planet. Great job, geographer! Keep exploring and learning about Earth's wonderful landscapes.