A health worker wearing protective clothing carries blankets towards the Ebola isolation ward, seen in the background, in Makemba, north eastern Gabon on Friday, Dec. 28, 2001. Ebola is one of the most deadly known viral diseases, killing 50 to 90 percent of those who become infected. Gabon-based researchers are going to use ESA-supplied satellite data to map the jungles where Ebola makes its home in unprecedented detail, with the aim of tracking down its as-yet unknown source.