SkyMatters: Looks like acid rain, dear — if you're having Christmas on Venus
Earth’s, The Venus Most This The Conclude Is Save Of 92 Pressure Surface Claus Santa On Than The That Us Greater Of The Robust Crushing Leaving To Could Times Only Christmas Presents, Magic On Atmospheric Even Planet
Santa has a lot to consider at this time of year. Flitting across the rooftops from town to town, country to country and continent to continent is no mean feat, especially as it all has to be done in one night.
But what if Santa had to do this on other planets as well? What extra challenges would he, his trusty reindeers and his present-packed sleigh face?
On Mercury, the closest planet to the Sun, Santa would immediately face the issue of the length of day. Mercury’s day lasts 59 Earth days, so there’s no way (beyond invoking some magic, which of course we expect to happen) that Santa can deliver all his presents at night. He would be faced with crippling temperatures of -173°C on the night side and +470°C on the day side and a continuous barrage of devastating particles from the Sun — and all without the protection of a magnetic field or an atmosphere that we have on Earth.
To make things even more miserable, particles from outer space on the night side would punch through his red cloak as if it wasn’t there.
And to cap it all, large doses of ultraviolet and X-ray radiation would require Santa and his reindeers to wear factor 10,000 sunscreen and sunglasses of the likes we have never seen (or need) on Earth.
From Mercury outwards to Venus. At more than twice the distance from the Sun, one would be forgiven for thinking the planet associated with romance would provide some respite. Santa would know better. As he plunged into the Venusian atmosphere sulfuric acid rain would eat away at any surface that was left unprotected. Upon landing, he would be met by a surface temperature of 464°C, the result of a runaway greenhouse effect hot enough to melt lead — a challenge for any kid’s toy.
There would be no escaping these soaring temperatures which are planet-wide. To cap it all, the atmospheric pressure at the surface is 92 times greater than Earth’s, crushing even the most robust presents, leaving us to conclude that only the magic of Santa Claus could save Christmas on Venus.
From Venus outwards again to Earth. Despite all the challenges faced by Santa that we read about every Christmas, delivering presents would be a comparative doddle on our home planet.
From Earth the next stop is Mars. At four times the distance from the Sun of Mercury and with no atmosphere to keep it warm, Santa would find a relatively benign planet that has a range of temperatures from +20°Cto about -150°C.
There would still be a need for sunscreen, as the Martian atmosphere is too thin to absorb damaging UV rays (albeit much fainter than on Earth) and his cloak would again be punched through by high-energy particles similar from space, similar to those encountered on Mercury.
At least on Mars the length of the day is similar to that on Earth, and with the planet being about half the size of Earth it would make for shorter journeys between present-dropping.
Out beyond Mars the challenges for Santa become ever more significant, though as all children will tell you, none are insurmountable for him.
On Jupiter, Saturn, Uranus and Neptune he would be battered by massive storms, huge magnetic fields, unbelievable lightning and, most problematical of all, nowhere to land. This is the regime of the gas giants, massive planets that dwarf the inner rocky planets, where the Sun looks like a bright star and a solid surface is nowhere to be found – except, that is, on their moons. With hundreds of moons to choose from, Santa, Rudolph and the other eight reindeers, would need all their magic to flit between them all.
For Christmas 2024, Venus, Mars, Jupiter and Saturn will all be visible in the night sky. For now there is no reason for Santa to visit them. But that prospect must surely give him sleepless nights.