The Nemesis theory has fallen into disripute due to a lack of evidence. While initially promising, further work indicated extinctions were more random. If it was true, it is irrelevant unless we are in one of the supposed high impact periods which were believed to be separated by 20 to 30 MILLION years. EP's tendency to blame every historical catastrophe on impacts and claims of a recent rise in impact rates is not supported by the majority of the astronomical community.

Furthermore, even if we were in one of the supposed peak impact rate periods in which both Mars and Earth had an elevated risk over "geological time", the lifeboat analogy still holds. We built most of our current civilization and technology in a mere century and our population over a few centuries. With the technology saved in a second branch of civilization our population would rebound even more rapidly. An similarly elevated risk over over thousands or millions of years does not negate the benefit of being able to rebuild in a few centuries.

E.P. Grondine
Continuing with the fallacies of "Lifeboat Mars"
Sun May 27 19:50:18 2001

EP Stated:
"Since I have not slept for over 36 hours, this is as good a time as any for me to spare you a few minutes of my time to explain to those interested some of the fallacies underlying the concept of "Lifeboat Mars."

Perhaps sleep deprivation explains the lack of clear thinking.

EP Stated:
"First, I'd like to thank Nick Hoffman for endorsing the idea of placing the priority of spending on NEo detection telescopes ahead of that of spending on manned Mars missions, or a Martian colony."

Hmm, wonder why that was so hard to say when similar comments have been made by others in the past.

EP Stated:
"It is further assumed by proponents of "Lifeboat Mars" that due to Mars' lack of atmosphere and athonosphere the consequences of major impact would be far less lethal to human beings there, than the consequences of such an impact with the Earth. Given the vast potential energy held in Mars' CO2 reserves, this is by no means certain."

Sure it's not certain that Martian colonists will be less susceptable to a major impact, but the key point is the far reduced chance of both being eliminated at the same time. The reduced risk aspect is simply a potential bonus. You further ignore the stepping stone nature of Martian colonization. Colonizing Mars will eventually lead to colonizing other worlds. We will have far more than 2 baskets eventually as long as we make the effort to get out of the first.

EP stated"
"In closing this note, if I remember correctly, we "just" (5 million years or so ago) passed through an arm of the Milky Way."

Sounds like we should be well past the peak risk then and back into the independent impact regime.

Sleep tight minny mite,
Mark