Earthrise Forty Years Later

There is no better way to end 2008 than with a look back at Earth in all her glory. One of the most famous, and most downloaded images, is the Apollo 8 Earthrise image taken almost exactly 40 years ago on December 24th 1968.

The image was taken as the Apollo 8 capsule crested the Moon and the astronauts looked back at Earth. The message back to Earth from the capsule was, "The vast loneliness is awe-inspiring and it makes you realize just what you have back there on Earth."NASA is well known for observing space but they have also been studying planet Earth for the last 50 years.

The NASA Earth Observatory website provides a catalogue of images and videos taken over the last six years, including scientific data from many earth imaging observation satellites. We have included a small sampling of images from 2008.

Wilkins Ice Shelf

In late February 2008, an ice shelf on the Antarctic Peninsula disintegrated into a floating pile of massive ice bergs, smaller ice fragments, and slush that was trapped in place by freezing sea water over subsequent weeks. The dramatic event was first spotted in NASA satellite imagery by Ted Scambos, lead scientist at the National Snow and Ice Data Center.

The disintegration of the ice shelf is most likely the result of rising temperatures on the Antarctic Peninsula, which over the past fifty years has been one of the most rapidly warming places on the planet.

Korea Demilitarized Zone

The UN Korean Demilitarized Zone (DMZ) separates the Republic of Korea in the south and the Democratic People’s Republic of Korea in the north. Not only a political buffer, the DMZ also protected the environment from humans in the past, but satellite imagery shows multiple burn scars to clear brush for surveillance, despite an agreement to stop burning that was signed in 2001. The image is from Landsat 7 thematic mapper. The darker the pink, the fresher the burn. Water is blue and vegetation is green.

Antarctic Ozone Hole

On September 12, 2008, the Antarctic ozone hole reached its maximum size for the year. NASA’s Aura satellite found that the ozone hole covered about 27 million square kilometers, making it larger than North America. Though larger than it was in 2007, the 2008 ozone hole was still smaller than the record set in 2006.

The ozone hole does not persist year round. It forms every spring in the Southern Hemisphere (August and September), when sunlight begins to return to Antarctica after the months of polar darkness.

Although the ozone hole is not the cause of global warming, the two man-made climate changes are related in other ways. The destruction of ozone has caused the Antarctic stratosphere to be cooler than it would normally be in the summer and fall.

Earthquake in Sichuan, China

A May 2008 earthquake in China’s Sichuan Province destroyed buildings and mountain ridges, with avalanches of rock. These false color images are from NASA’s Terra satellite. The river is blue and vegetation is red, blue-gray indicates bare ground, buildings, and paved areas. The bare ground from the landslides is shown along the ridge tops. The landslides blocked many rivers and created new lakes that threatened nearby towns. More than 68,000 people died, 360,000 injured and 21,000 missing.

Pingualuit Crater, Canada

This impact crater was formed about 1.4 million years ago. There are 20 other impact structures in eastern Canada. The Pingualuit Crater has provided useful information about climate change from the last ice age.

With a diameter of 3.44 kilometers (2.14 miles), the Pingualuit Crater has a lake about 267 meters (876 feet) deep. The lake sediments have not been disturbed since before the Pleistocene Ice Age and continue to provide valuable scientific data since first being explored in the 1950s.

The high latitude of the area limits vegetation, so thick, lush forests do not flourish in this region. In fact, the crater’s name derives from an Inuktitut term for cold-weather-induced skin blemishes.

Visit NASA Earth Observatory: www.earthobservatory.nasa.gov

Trevor Williams is a University of Victoria Mechanical Engineering PhD candidate specialising in renewable energy, power grid modeling and plug-in hybrid electric vehicles. He has a bachelors in Aeronautical Engineering, a Masters in Management Science and over 23 years international experience in the space industry, having worked on Earth observation and telecommunications satellites.