“A manned mission to Mars will be underway or will have actually arrived there by the time Long Bets posts Prediction 1000.”

It took so many months for the last few predictions to be added that I actually asked Long Bets if they were the objects of a court injunction. The truth is, people just aren't terribly interested in donating money in this fashion, even to worthy nonprofits. There is more actual interest in flying to Mars (as several of the last 100 predictions indicate).