Natural Environment Blog

I recently wrote about the Crew Earth Observations experiment, where crew of the International Space Station photograph the Earth.

Although photographing Earth only takes up a small portion of their time - between 10 to 15 minutes per day - these photos are a crucial part of analyzing our ever changing planet.

So, every day there are astronauts up there in the sky taking photos of us here on Earth. But before you get all paranoid, did you know that the International Space Station can actually be seen from Earth?

The International Space Station can be seen from Earth with the naked eye. It orbits the Earth at an average speed of 27,700 km (17,210 statute miles) per hour, completing 15.77 orbits per day. And, because it orbits at approximately 350 kilometers above the Earth, it is close enough to see as it zooms past your region.

To find out when the International Space Station is next traveling past your town, check out the Heavens Above website.

NASA astronauts have shared their top ten photographs of Earth as taken from space.

The photos have been taken as part of the Crew Earth Observations (CEO) experiment. The CEO experiment is an ongoing mission to provide people on Earth with data about our ever changing planet.

Astronauts have been taking photos of Earth since the early 1960s. Nowadays, the CEO experiment continues on the International Space Station (ISS), which hovers around 220 miles (354 kilometers) above Earth.

The photos to the right are included in the top ten Earth observations. The top photo was taken when Mt Cleveland erupted for about two hours in 2006.

The second photo shows what the Himalayas look like from the International Space Station. This photo includes Mount Everest (the world’s highest mountain) and Mount Makalu (world’s fifth highest mountain).

The astronauts on the International Space Station spend between 10 and 20 minutes per day taking photos of Earth. They use hand held cameras, which include 35 and 70 mm cameras.

Areas to be photographed are both pre-determined, and decided by the crew. The pre-determined areas are generally regions of Earth that have undergone change or are indicators of global change.

Many of the pre-determined sites include major deltas in south and east Asia; coral reefs; smog-prone urban regions; areas experiencing major floods or droughts triggered by El Niño cycles; high altitude glaciers, which reflect longer-term climate changes; faults associated with major tectonic plate boundaries; and unusual features on Earth, like impact craters comparable to structures on other planet.