Metaculus Help: Spread the word
If you like Metaculus, tell your friends! Share this question via Facebook, Twitter, or Reddit.
Will the number of living humans who have walked on another world fall to zero?
In 2011, cartoonist Randall Munroe published a graph showing the number of living humans that have walked on another world. It rose in 1969-1972 to a peak of twelve Apollo astronauts, then declined in the nineties with the deaths of James Irwin, Alan Shepard and Pete Conrad.
In the current decade, with the deaths of Neil Armstrong (2012), Edgar Mitchell (2016), Eugene Cernan (2017) and John Young (2018), the number has fallen to five living astronauts. Randall Munroe predicted in 2011 that the last man would die between 2023 and 2035 with 90% confidence.
Several countries (as well as the company SpaceX) have announced plans for manned landings on the Moon or on Mars in the 2020s or 2030s, which would increase the number for the first time since 1972.
Will the number fall to zero before the next increase?
Negative if any human lands on another planet or a moon and walks on the surface while there is still a living Apollo astronaut who walked on the moon.
Positive if/when the last Apollo astronaut dies, otherwise.
Metaculus help: Predicting
Predictions are the heart of Metaculus. Predicting is how you contribute to the wisdom of the crowd, and how you earn points and build up your personal Metaculus track record.
The basics of predicting are very simple: move the slider to best match the likelihood of the outcome, and click predict. You can predict as often as you want, and you're encouraged to change your mind when new information becomes available.
The displayed score is split into current points and total points. Current points show how much your prediction is worth now, whereas total points show the combined worth of all of your predictions over the lifetime of the question. The scoring details are available on the FAQ.
Note: this question resolved before its original close time. All of your predictions came after the resolution, so you did not gain (or lose) any points for it.
Note: this question resolved before its original close time. You earned points up until the question resolution, but not afterwards.
This question is not yet open for predictions.
Metaculus help: Community Stats
Use the community stats to get a better sense of the community consensus (or lack thereof) for this question. Sometimes people have wildly different ideas about the likely outcomes, and sometimes people are in close agreement. There are even times when the community seems very certain of uncertainty, like when everyone agrees that event is only 50% likely to happen.
When you make a prediction, check the community stats to see where you land. If your prediction is an outlier, might there be something you're overlooking that others have seen? Or do you have special insight that others are lacking? Either way, it might be a good idea to join the discussion in the comments.