I want to address several issues mentioned by Ben Jones in his October 9 article “The hidden danger of the Cassini probe.”

He cites an estimate that one pound of plutonium is “enough to KILL every LIVING THING on Earth.” He doesn’t cite the source, though. I believe I saw that estimate and it actually stated that if dispersed evenly on the Earth’s surface, one pound is enough to cause lung cancer in every man.

Those are different things, wouldn’t you agree?

Of course, I am not saying lung cancer is any better or that it is possible that there are several estimates, but it’s a good practice to cite your sources of “scientific estimates.” (It’s good not to be Popular Science.)

Also, Jones said the “Titan rocket carrying the probe has an estimated 90 percent chance of success.” Success in what? Takeoff? Mission? Something else?

Mr. Jones also mentions the Challenger catastrophe. Just recently, I read a report by the late Richard Feynman, world-famous physicist and Nobel Prize winner who served on the congressional committee that investigated the explosion. ( It is part of his book “What Do You Care What Other People Think: Further Adventures of Curious Character.”)

He actually cites the NASA estimate for the takeoff explosion as 1 in 100,000. After talking to engineers and technicians in the Kennedy Space Center, he recommended a more conservative estimate of about 1 in 1,000 or even 1 in 300. Mr. Jones’ figure is 1 in 10.

The feature article in Popular Science is not the best source of information, in my opinion. Mr. Jones rightfully had some questions and doubts, but all he did was pursue the same magazine, and he “finally gave up.”

The Russian rocket accident in 1996 caused worldwide increase in lung cancer. Again, where is the source?

I am not a medical researcher, but my father is and I am also a science major. I seriously doubt that one year is enough to gather valid evidence for population health research, especially on cancer.

Finally, Mr. Jones calls us to participate in halting the launch and even protesting further missions if the Cassini mission goes smoothly. Yeah, of course — the more NASA succeeds, the more dangerous they are, aren’t they?

Just a general caution. I understand that sophomores in English may not have a clear idea about how to present a scientific issue (sources, justifications etc.)

Nevertheless, if you take on such a mission, there is little excuse for amateurism. “Ask — people know.” (I think there is a department of aerospace engineering here.)

Ekaterina Kadnikova

Graduate student

Organic chemistry