(Click to enlarge)
Above, a CALIPSO vertical profile from space shows the smoke plume June 3 from the wildfires currently raging in Arizona. It is overlaid on an image captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on the Terra satellite nine hours later. CALIPSO and Terra are part of the "A-Train" constellation of five Earth-observing satellites. (Credit: NASA/Kurt Severance, Jason Tackett and the CALIPSO team)
June 7 marked the fifth year in space for the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite. Since its launch April 23, 2006, CALIPSO has traveled 750 million miles (1,207,008,000 km), and along the way has generated data that would fill about 10,500 DVDs or 75,000 CDs. It captured its 3 billionth image on June 8.
How has it been able to take that many shots? CALIPSO sends out 20 laser pulses every second, and each is only 20 billionths of a second long. That's a lot of profiles observed, "but if you add all the pulses up, the laser has only produced light for one minute," said Chip Trepte, CALIPSO's project scientist, based at NASA's Langley Research Center in Hampton, VA.