NASA launched the first of seven Nimbus spacecraft to study Earth from space in August 1964 and fifty years later experts at the National Snow and Ice Data Center in Boulder, Colorado are recovering long-lost images from old Nimbus data tapes and black-and-white film. The preliminary findings from long-lost images from the 1960’s have produced some big surprises with respect to global sea ice. In much the same way archeologists dig up artifacts that can rewrite history, these long-lost satellite images have to potential to rewrite our knowledge of ever-changing global sea ice cycles.

Nimbus satellite observations were transmitted as an analog signal and then burned onto film and stored in canisters labeled only by orbit number (i.e., no indication of geography). The only way to retrieve this imagery data into useable format was to scan all of it which meant 250,000 images. Now the satellite imagery data is completely digital and can be managed and manipulated by scientists in order to get a look at the past. Preliminary work with the now-digitized satellite data has been from the period 1964 to 1969 and the year 1970 is now being analyzed.

Indeed, early findings have been quite surprising with respect to both the Arctic and Antarctica sea ice extent. According to NASA scientists, there have been “enormous holes” found in the Arctic ice that “we didn’t expect and can’t explain” in a decade considered to be colder-than-normal (i.e., the 1960’s). The Antarctica sea ice extent findings are perhaps even more amazing. Using these long-lost satellite images, it appears that the Antarctica sea ice extent reached record highs in 1964 only to be followed by record lows just two years later in 1966 and also the earliest maximum sea ice extent was seen in 1969. As is often the case with more data, it often leads to more questions than answers. Video discussion on this by NASA scientists at http://www.youtube.com/watch?v=bvGIE1y3cXA.