We are living at the greatest moment in history for finding life beyond Earth. We have robots poking and sniffing around on Mars. We have a space probe in the works that will take a close look at Europa, to examine the likelihood of life on an ice-covered ocean world. Above all, we no longer have to wonder if our solar system is unique: We know of thousands of planets around other stars, and it’s clear that the total number of planets in our galaxy alone must number in the billions, if not the trillions.
But with all these rapid advances have come acute intellectual growing pains. It is only natural that people want to know how many of those distant planets could truly support life — to know whether living worlds like our own are common or rare (or unique). The desire for answers runs far ahead of the ability of science to provide them, unfortunately. And so we end up with whiplash conclusions based on the latest speculative study: Red dwarf stars are great places to find habitable planets … or maybe they are deadly. Earth couldn’t sustain life without the Moon … or maybe the Moon is not necessary at all.
