Some days you might be so happy that you feel like you're standing on top of the world. Would you believe that some people have literally stood on top of the world? It's true!

Those who have climbed all the way to the summit of Mount Everest — the highest mountain on Earth — can say they've gone as high as they can on this planet. And how high have they gone? A whopping 29,029 feet (8,848 meters) — about 5.5 miles! — above sea level, to be exact.

Mount Everest wasn't always the highest point on Earth, though. About 60 million years ago, two of Earth's tectonic plates — the Indian and Asian plates — collided and started pushing huge mounds of rock into the sky. The result was the Himalayan mountain range with Mount Everest as its highest peak. Today, Mount Everest is still growing at the rate of about one quarter-inch per year!

Even though Mount Everest has been around a long time, it's only been explored over the past couple hundred years. In 1841, Sir George Everest led a British survey team that first identified Mount Everest and called it Peak 15. It was later renamed Mount Everest in honor of Sir George Everest.

The summit, or highest point, of Mount Everest sits at an elevation that many airplanes usually fly at, and it's higher than birds fly. The summit actually marks the border between Nepal to the south and Tibet to the north. People in Nepal call Mount Everest “Sagarmatha," which means “Goddess of the Sky." People in Tibet call it “Chomolungma," which means “Mother Goddess of the Universe."

The summit of Mount Everest juts into the jet stream, a powerful wind current high up in the Earth's atmosphere. This means that the top of Mount Everest can experience wind speeds of over 200 miles per hour and temperatures as low as -80° F.

Such weather conditions would make it nearly impossible to stand on Mount Everest's summit. Twice each year, though (in May and November), the jet stream moves just far enough north to allow climbers to try to reach the top while the winds are calm and temperatures are warmer. Climbers call these periods “summit windows."

Climbing to the top of Mount Everest is no easy task, though. The first people ever to reach the summit were Sir Edmund Hilary from New Zealand and Tenzing Norgay from Nepal. They reached the summit of Mount Everest on May 29, 1953.

Since then, thousands of people have reached the summit. Unfortunately, many climbers have died while making the attempt. Because of its high altitude, it takes approximately two months to make the climb, because the human body must have plenty of time to adjust to the lack of oxygen at high altitudes.

Climbers also face a multitude of other obstacles. In addition to extremely cold weather, climbers face rough terrain. As well as carrying things like tents, sleeping bags and food items, climbers must use special climbing gear. This includes special spikes — called crampons — on their boots, ice axes, nylon ropes, ladders and oxygen tanks to make their trek to the top.

Fortunately, climbers get a lot of help from the people in Nepal who live near Mount Everest. These people — called Sherpas — serve as climbing guides and help carry supplies between base camps along the climbing routes.

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