[Brett66]

I definitely remember those protesters and they were led by Michio Kaku, a brilliant physicist, who I no longer have any respect for because of that. They made wild claims about how everyone on Earth could get cancer if Cassini crashed into the Earth. Mr. Kaku did a not-so-brilliant analysis of how it was mathematically probable and put his mug in front of the cameras whenever possible. NASA has tried to court environmentalist support, this is a classic case of why they should be wary of such an alliance, they will turn on them in a heartbeat while being driven to a frenzy by junk science.

Here's an article written around 1997 about some of their "theories":

Cassini's Night Ride

[Lonesome in Massachussets]

They made wild claims about how everyone on Earth could get cancer if Cassini crashed into the Earth.

University of Pittsburgh health physicist Bernie Cohen has offered to eat a weight of plutonium equal in mass to the amount of caffeine that Ralph Nader would be willing to eat. His point was that taken orally - ingested - plutonium has the same specific toxicity as caffeine.

Ralph Nader used to claim that if a pound of plutonium was released into the environment it would end life on the Earth. The Russians performed the experiment at Chernobyl of releasing about 2500 pounds of plutonium. If life on Earth has ended, the suppression of this fact is the singularly most successful disinformation campaign in world history.

Nader's claim was based on research that showed that inhaled - as an aspirate - one pound of plutonium can induce two-million cases of lung cancer. Since the population of the Earth in the 1950's was about two-billion (10^9) Nader borrowed three orders of magnitude out of open stock, used the wayback machine to knock off a couple decades and redefined "life" to mean "human life". He left unanswered how a pound of plutonium released into the environment would transform itself into an aspirate, go back in time several decades, multiply itself by three orders of magnitude and then magically uniformly distribute itself into the lungs of all two-billion people. Or why all other lifeforms, seeing the demise of the human race would simply stop existing. Other than that he was on to something.