Space

Across the void of space, the other planets in our solar system all have environments that are hostile to life as we know it. Our nearest neighbor, Venus, has been visited by probes to gather information about its surface - as has Mars - but humans have yet to discover ways to send astronauts to these planets, as the journeys themselves would be just as dangerous as the final destination. This fact hasn't stopped engineers from both the American and Russian space programs from trying, though!