What If Mercury And Neptune Swapped Places? | Unveiled

What If Mercury & Neptune Swapped Places?

Our solar system consists of eight planets in predictable, consistent orbits around the Sun. They’ve orbited like clockwork for billions of years, each planet adapting to its specific placement in space. But what if their positions were suddenly reversed or thrown out of order?

This is Unveiled, and today we’re answering the extraordinary question: What If Mercury and Neptune Swapped Places?

It might not seem like it, but each planet is in the precise position it needs to be in order to maintain its orbit. A planet’s orbit involves a perfect balance between its forward motion and the gravitational pull of the Sun and other large bodies in the Solar System. These orbits and positions are also responsible for some of the planets’ characteristics.

Let’s look at the specific characteristics of both Mercury and Neptune to understand their importance. Mercury, the closest planet to the Sun, travels the fastest in its orbit. It’s the smallest planet as well, barely bigger than Earth’s own moon. From Mercury’s surface, the Sun would appear three times bigger than what we’re used to on Earth, and seven times as bright. Despite this, it’s not even the hottest planet, as its atmosphere is too thin to trap much heat. This causes the temperatures to range from 800 degrees fahrenheit in the day to -280 at night. And because it’s so close to the Sun and so small, it can’t hold on to any moons of its own.

Neptune, the farthest planet in orbit around our Sun - excluding dwarf planets like Pluto - doesn’t have this problem. It has 14 moons to call its own and even five planetary rings. About 80 times farther from the Sun than Mercury, Neptune is a cold and dark planet with violent, supersonic icy winds. These winds can reach speeds of up to 1,300 mph. It’s four times the size of Earth, but 17 times the mass, with most of this mass composed of hot, dense fluids.

So what would happen to these planets if they suddenly swapped places with each other? What if Mercury became the farthest planet from the sun, and Neptune the closest? For starters, Neptune would lose some of its smaller moons as the Sun overpowered its gravitational pull. It would also get a lot hotter! And despite Neptune being called an “ice giant”, it’s already packing some heat down in its mantle and core! While the temperature of its outer atmosphere is a chilly −360°F, its mantle can reach temperatures of 8,500°F! Thanks to this heat, the temperature of Neptune’s cloud tops are actually comparable to Uranus’, even though Neptune gets only 40% as much sunlight. So if Neptune were thrust so much closer to the Sun, it would warm up very quickly indeed.

Over time, the Sun would affect Neptune’s atmosphere, as it does Mercury’s. Neptune’s atmosphere is composed of hydrogen, helium, and trace amounts of methane. It’s this methane that gives Neptune its blue appearance, absorbing the red light from the Sun. While Neptune’s mass affords it a greater hold over its atmosphere than Mercury, it’s likely that solar winds would still take a toll. Its rings, composed of ice and dust, would also take a beating. And its moons would soon start losing some of their icy mass. Neptune’s largest moon Triton is composed of frozen nitrogen, a water-ice crust, and icy mantle, which would all start to heat up.

And what about Mercury, now at the back of the planets’ marching order? Deprived of sunlight, the barren landscape, which once alternated between extremely hot or extremely cold, would now just get colder. Its orbit, once the shortest, would now become the longest. It would become something like another Pluto, orbiting in the far reaches of the solar system in freezing darkness.

The orbits of other planets would also change, as Neptune’s gravitational pull suddenly moved places. Currently, the planets’ orbits exist in a stable equilibrium, but if Mercury and Neptune swapped places, this balance would be disrupted, in a potentially disastrous domino effect.

The other inner planets, Venus, Earth, and Mars, would be drawn out of their current orbits towards Neptune. Meanwhile, the outer planets, no longer subject to Neptune’s pull, could also drift inward. And the more that the largest planets like Jupiter, Saturn, and Uranus drifted, the more they’d would disrupt the orbits of the other planets. It would be chaotic and difficult to predict where exactly they’d end up, and take many years for them to regain a consistent, stable orbit.

This would be very bad news for us here on Earth. Earth’s sits in the Sun’s “habitable zone” or “Goldilocks Zone” at a distance that’s not too hot and not too cold for life. Regardless of the direction Earth was pulled towards in the ensuing orbital mayhem, it wouldn’t be good! On the up side, at least we’d have a nice view of Neptune lighting up the sky as it sailed across the horizon!

Currently, we can juuust make out Mercury with the naked eye, but only right before sunrise or after sunset close to the horizon, because its orbit is so much closer to the Sun than our own. This means that most of the time it’s behind or in front of the Sun. Given its size however, Neptune would make quite an impression in the night sky! So hey, at least we could enjoy the view before the Solar System’s orbits all went haywire!

And that’s what would happen if Mercury and Neptune swapped places.