Humans don’t have a defined mating season like deer or wolves. Here’s how evolution blended biology, culture and social life into year-round intimacy.

As private companies race to build orbital habitats and government agencies sketch out Mars timelines, a fundamental ...

As commercial spaceflight edges closer to reality, astronauts spend more time orbiting Earth, and as we look to one day settle on Mars, questions about sex and reproductive health in space need to be ...