The Voyager engineers calculated over 10,000 launch windows so that encounters between the craft and the planets on its trajectory didn't happen during Thanksgiving or Christmas, allowing them to stay home for the holidays.
Almost 99% of the mass of the human body is made up of six elements: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only about 0.85% is composed of another five elements: potassium, sulfur, sodium, chlorine, and magnesium.
10% of Europeans are naturally immune to the HIV virus due to a genetic mutation. Scientists believe this mutation was a result of all the plagues in the middle ages. So your ancestors survived the time of The Black Death and The Pox, and today you're immune to HIV.