If you think that scouting the moon and Mars is a better use of spacecraft than observing the Earth itself, then that’s fine as your preference, but it’s not what the letter said.

Greg: Sure, I think they are all interesting, but we aren’t going to Alpha Centauri any time soon, so it is inherently less interesting to me that Earth’s moon and Mars, where we are going soon (maybe). In a world of limited budgets, you have to prioritize. I strongly believe that the highest priorities, right now, should be the places that we can establish bases and get trade started soon, even if that means everything else has to go. Once we are out there, there will be plenty of science and technology just from being there. But, if we spread ourselves too thin studying Alpha Centauri where nobody is going soon, then we will never go anywhere.

If your a Spaniard looking for the new world, do you build a really big telescope on your home turf and watch the coastal islands from a distance? Or, do you build ships and go explore those islands and then venture outside the Medeterranian and find the new world? If you can afford to do both, you probably do, but sending ships ultimately gets you a lot more bang for your buck.

If you have to choose, choose the ships.

— Donald

And so is the science and technology, unless you think that the moon and Mars are the two most interesting stellar bodies in the universe, with the Earth in third place. Most scientists and most technologists think that the Earth is more interesting than the moon or Mars, and that things farther away than Mars are also interesting.

Steven Squyres
http://www.usnews.com/usnews/culture/articles/040119/19mars_2.htm

But fans of human space travel can take comfort in one team member’s observation that it will take each rover about three months to do what a human geologist could do in a weekend.

I recall a quote, possibly from an Academy of Sciences report or possibly the Aldridge report, stating in effect that a field geologist could accomplish as much science in a few days as the Rovers have on Mars in months. I cannot find that in an Internet search.

Does anyone else recall that quote? If so, do you have the exact quote and where it came from.

Thanks!

— Donald

Put it another way, what does more for astronomy? Maintaining Hubble and the automated “space science” endeavors of today, or placing human laboratories to get detailed absolute compositions, stratigraphies, and ages for many different terrains on Earth’s moon, nearby asteroids, and Mars and its moons? The science would be different and you could make a strong case for either one. My point is that the answer is not automatically the former.

— Donald