Sao Paulo, Brazil, at Night

High-resolution image (678 Kb)

A favorite activity of astronauts and cosmonauts aboard the International Space Station is looking at the city lights below when the station crosses the Earth's dark side. The lights outline the densest population centers, coastlines and suggest cultural patterns. Taking these low-light images using the equipment on board the station has been challenging to the crewmembers because of the long exposure times required. Astronaut Don Pettit, who left the station for Earth on May 3, 2003, has pioneered an approach using a home-made tracking system to track the ground as it moves relative to the station, allowing him to acquire long-exposure images under low-light conditions. Don's ingenious "Barn-Door Tracker" is a camera mount with a rigged with a hand drill to create a motion tracking system.

This image shows the sprawling urban footprint of Sao Paulo, Brazil, South America's largest city of roughly 17 million people. The different colors (pink, white and gray) define different types and generations of streetlights. The port of Santos is also well defined by lights.

Astronaut photograph ISS006-E-44689 was taken with a digital camera on April 12, 2003, and is provided by the Earth Sciences and Image Analysis Laboratory at Johnson Space Center. Additional images taken by astronauts and cosmonauts can be viewed at the NASA-JSC Gateway to Astronaut Photography of Earth.