Astronaut photography of the Earth from the
International Space Station has achieved spatial resolutions
of less than six meters, an analysis of more than 13,000
images has shown. This means scientists can use photographs
taken from the space station to study changes that are
occurring in very small features on the Earth’s surface.

The results of this study are discussed in an article in the
April 23 edition of the American Geophysical Union journal
Eos Transactions.

“The sharpness of the photographs taken by the station
astronauts surprised both them and the scientists on the
ground,” said Dr. Julie Robinson, lead author of the paper
and a Lockheed Martin scientist in the Earth Sciences and
Image Analysis Laboratory at NASA’s Johnson Space Center in
Houston. “It has really changed our view of how much detail
humans can photograph from orbit.”

The first three resident space station crews took 13,442
images of the Earth using digital still cameras, 35-mm
cameras, 70-mm cameras and a variety of lenses. Crewmembers
were able to produce higher-resolution photographs with the
high-magnification lenses by learning to compensate for the
relative motion of the Earth below while pointing cameras
through a specially built window in the station’s Destiny

“Astronauts now consciously track the ground when
photographing the Earth,” said Dr. Cynthia Evans, co-author
of the paper and the manager of the Earth Sciences and Image
Analysis Laboratory for Lockheed Martin Space Operations.
“Their digital cameras provide instant feedback, allowing
crewmembers to refine their tracking and focus techniques.
Because each crew has demonstrated this capability, we can
reliably plan for scientific studies that require more
detailed imagery that might not otherwise be available to
Earth Science researchers.”

“Since the birth of the space program, astronaut photographs
of the Earth have engaged the public,” Robinson said.
“Scientists also use these photographs as valuable records of
the state of the Earth. With new digital technologies, and
high-resolution capabilities, astronauts on the International
Space Station continue to acquire Earth imagery that has
scientific relevance.”

A searchable database containing more than 30 years of
astronaut photography is available on the Web at: