&quot;Had there been any malfunction causing the Cassini space probe to collide with the Earth, NASA&#x27;s complete environmental impact study estimated that, in the worst case (with an acute angle of entry in which Cassini would gradually burn up), a significant fraction of the 33 kg of plutonium-238 inside the RTGs would have been dispersed into the Earth&#x27;s atmosphere so that up to five billion people (i.e. almost the entire terrestrial population) could have been exposed, causing up to an estimated 5,000 additional cancer deaths (0.0005 per cent, i.e. a fraction 0.000005, of 1 billion cancer deaths expected anyway from other causes), but the chance of that happening were less than one in one million.&quot;<p>Would it be true to say that your loved ones are thousands of times more likely to die in a car crash than in the worst-case scenario of this project?<p>This is a stupid reason for having an outcry.