Satellite observations of Brazil in the 1970s, critical for establishing a time-line of changes in the Amazon basin, are also lost on the now obsolete tapes to which they were written [1]
[1] Garrett, J & Waters, D. Preserving Digital Information. Report of the Task Force on Archiving of Digital Information commissioned by The Commission on Preservation and Access and The Research Libraries Group. 1996 http://www.clir.org/pubs/reports/pub63watersgarrett.pdf p. 3