It doesn't take much to convince people that they've seen an experimental missile or UFO. A funny-looking cloud or an exceptionally bright planet will usually do the trick. Here, Life's Little Mysteries' top 7 things that drive space hoaxes
The average American is exposed about 620 millirem (mrem) of radiation each year, according to the United States Nuclear Regulatory Commission. This radiation comes from both natural and man-made sources.