Q 3.10 What is the chance of an individual being struck by a falling space debris?

To determine accurately the probability of a person being struck by space debris is at best an educated guess due to numerous unknowns that include – detailed construction of debris: shape and construction determine how an object disintegrates during re-entry; difficult to predict atmospheric behaviour; random tumbling motion of the debris and hence drag, uncertainty in location where a debris can fall, probability of a person being present at the location of impact.

Indicative probability based on various simplifying assumptions have been proposed. A given debris likely to re-enter the Earth would reach the Earth with a very low probability;  the object’s likely impact location could be estimated by noting its orbital location at entry point; the impact point could then be superimposed on world’s population grid. Assuming a total population as 7 billion, the odd of an individual being struck was then estimated by According to analysts in Orbital Debris Program Office at NASA’s Johnson Space Center as 1 in 3200 and the probability of a given individual being struck was thence estimated as 1 in several trillion.

According to scientists in Orbital debris program office of European Space Agency orbital debris program the probability of an individual being struch by falling debris is 1 in 100 billion and over an individual’s lfe time spanning 75 years the chances are increased to 1 in 10 billion. To provide a perspective it is mentioned that the probability of someone being struch by lightening is 60000 times greater and being involved in a serious car accident 27 million greater.

3.10-1 Natalie Wolchover, September 21, 2011, 12:30 ET”What are the odds you’ll get struck by a falling satellite, (Live Science.com, https://www.livescience.com/33511-falling-nasa-satellite-uars-risk.html

Retrieved 2/3/2018).