The Earth is the only known habitable planet in the solar system, yet curious minds still wonder: what would happen if you visited another world without a space suit and how long would you survive there? While the answer seems obvious at first glance, you’d be surprised to know that the circumstances vary greatly from one planet to the next.
Mercury, for example, is rather peculiar. Its proximity to the Sun means that one side of the planet can reach scorching temperatures that exceed 430 degrees Celsius, but Mercury rotates so slowly that the cooler side can dip below -180 degrees Celsius. If you visited Mercury, you’d either freeze or bake to death, depending on which side you walked on.
Venus also sports extreme temperatures, but not because of its proximity to the Sun; instead, its dense atmosphere is to blame. Greenhouse gasses in Mercury’s atmosphere trap heat from the Sun, resulting in temperatures that exceed 470 degrees Celsius – that’s hotter than Mercury. Consequently, you’d be vaporized if you even tried to set foot on Venus.
Mars is perhaps the only other potentially-habitable planet in our solar system, but you still couldn’t live there without a space suit. It’s relatively cool with an average annual temperature of -60 degrees Celsius, but Mars lacks an Earth-like atmospheric pressure. Upon stepping on Mars’ surface, you could probably survive for around two minutes before your organs ruptured.
Jupiter is another no-go zone, as the gas giant lacks a solid surface to stand on. Upon entering the planet’s atmosphere, you’d fall and fall – but you wouldn’t survive until the end of the drop because the planet’s immense pressure would do you in beforehand. Sadly, the conditions are quite similar on Saturn, so we’ll move on.
As for the final two full-sized planets in the solar system, Neptune and Uranus share similar properties. Both are incredibly cold, between -214 and -224 degrees Celsius and sport atmospheres comprised of methane gas. Assuming you survived the long trip to either of these planets, you wouldn’t last on the planets themselves because you’d either freeze to death or asphyxiate.
Indeed, Earth is just perfect enough to survive without a spacesuit. Given just how beautiful Earth is, who’d want to live anywhere else anyway?