From ice volcanoes to hundred-metre snowdrifts: Seven frigid planets
Sunday, January 5, 2014, 5:21 -
We think it's safe to say this winter has been a little harsher than usual so far.
This very weekend, the Prairie provinces are shivering in extreme windchills, the Atlantic provinces are digging out from one storm and preparing for another, while southern Ontario is poised for snow, rain, and a very rapid cooldown that will make for terrible driving conditions on Monday.
STORM WATCH: You can tune in on TV for rolling coverage of the Ontario storm, and read up on the details here.
As lousy as it can get in this country at wintertime, just remember: It's way, WAY worse on other planets.
Here are just seven planets and moons in our home system with weather that should make you grateful to be on Earth.
The closest planet to the sun has frozen ice on it
Talk about a weird place to lead off an article on cold planets – Mercury, closest planet to the sun, almost three times closer to our home star than Earth is.
Certainly, the side facing the sun is hot enough to bake an oven pizza in about 20 minutes or so (about 430C, for those of you who don’t prefer your science in culinary terms).
But the nightside gets down to around -180C, more than twice as cold as the coldest temperature ever recorded on Earth.
It also turns very slowly, such that one “day” on Mercury is equal to 58 days here on Earth, so the parts that are in shadow are in the deep freeze for a loooooong time – complete with water ice, believe it or not.
Yep, water ice. See this pic:
Those red areas are shadowed parts of polar craters, whose walls are at such an angle that they have NEVER received direct sunlight. And just last year, NASA’s MESSENGER probe confirmed that in those shadows are pockets of water ice, hidden beneath a thin, darker layer of organic compounds.
This source even says the water ice is “pure,” although the good folks at NASA are regrettably silent about its suitability for beach-side cocktail ice cubes.
Mars has overnight lows of 110 below
The planet Mars excites astrophiles, thanks to evidence it once supported abundant water supplies and may have once harboured at least microbial life.
It’s got an atmosphere mostly of carbon dioxide. But while it’s thick enough to be highly visible in low orbit, it’s also very, very thin. NASA is looking into what caused it to become so thin:
Temperature-wise, that thin atmosphere means it’s very hard for the planet to retain heat, so when the mercury falls, it falls HARD … down to overnight lows of around -110C in the winter.
We know that from the many probes that have visited the planet, including several rovers, like Spirit and Opportunity from the last decade, who encountered temperatures so cold, it broke some of their sensors.
The planet even has frost, very thin, but lasting for 100 days at a time in certain parts of the planet:
The plus side? It gets up to around 35C in mid-summer, apparently high enough to generate enough atmospheric warming to allow for dust devils.
So if you’re shivering in -30 windchills, take heart! Just one planet over, it’s about as toasty as your average Ontario summer. That knowledge probably won’t improve your mood much, but still, pretty neat, eh?
Europa's icy seas may teem with life
No chance of dust devils on Jupiter’s moon of Europa – and, with lows of less than -180 Celcius, no chance of a visitor encountering anything remotely resembling warmth. On the surface, at least.
That criss-crossed surface may actually cover a deep water ocean, according to NASA. It’s been long theorized that beneath the surface could be liquid water or slushy ice, which leaves the intriguing possibility of crude life actually existing down there.
The idea is, tidal warming could mean the water is warmer than the planet surface, and shielded from Jupiter’s stiff radiation field.
And, as in Earth’s own deep oceans, microbial life could possibly be warming its microbial toes around underwater volcanic vents.
That’s the theory, anyway, and it depends VERY strongly on just how deep and warm that supposed ocean is, and the environment certainly couldn’t support any kind of complex lifeforms.
So finding out for sure may be a little more complicated than sending an astronaut with a saw, a fishing rod and a lot of patience.
Io gives you a choice between flash-freezing, and burning lava
If you’re wandering around Jupiter’s neighbourhood, and fancy something a bit warmer than mysterious Europa, you can nip on down to Io, another moon that is less mysterious and considerably more terrifying.
Temperatures down there average around -130C, so it is a little toastier than Europa, but if you skip over to any of those acne-like features, prepare to get WAY toastier.
Because it’s so close to the enormous gravity of nearby Jupiter, the tidal forces on Io are just ridiculous, with parts of the crust being pushed and pulled up and down by around 100 m. Just like tides on earth, only made of solid rock instead of water.
The result of all this friction? An absurd amount of volcanoes, around 400 or so, blasting sulfur into the planet’s thin atmosphere in plumes 300 km high (like the one about 43 seconds into the video below).
Each one burns at around 1650C, so there are lakes of lava and floodplains covered in liquid rock.
And if you step away from those hot zones, into the areas where there’s no heat, you might find yourself in ankle-deep sulfur dioxide snowfields.
So if you’re annoyed at how cold it is outside, be grateful it’s not Io. As far as weather deprivation goes, it’s hard to beat being flash-frozen AND incinerated, depending on where you’re standing.
The rains of Titan are made of methane and last for decades
If Jupiter’s moons aren’t to your liking, you’ll not find much better in Saturn’s neighbourhood.
Titan, for example, is one place where you’ll not only shiver in -178C, you’ll also be smashed by arguably the worst weather in solar system outside of Venus.
That thick, hazy atmosphere up above is a mixture of nitrogen and methane, and is actually thicker than Earth’s.
It’s also the only outer planetary body where you’ll find any kind of rain. A hellish rain made of methane, which can survive in liquid form in those absurdly cold temperatures.
And when it rains, it RAINS. Parts of the moon may go without precipitation for decades, but when the skies do finally open up, a deluge of hydrocarbons scours and remakes the landscape, on its way to rivers and lakes made of methane.
We didn’t have a very clear idea of all of this until last decade, when NASA and the European Space Agency sent the Huygens probe to the surface:
If nothing else, we can thank the probe’s inventors for giving us yet more proof that although -40 windchills are a real pain, it's better than being drowned in an oily alien rain at the same time.
Enceladus' volcanoes are made of ice
If blazing hot volcanoes aren’t your bag, how about freezing cold ones?
Here’s Enceladus, another of Saturn’s moons:
And every now and then, massive plumes of water ice and other minerals will spew from them, far, far into the atmosphere:
At around 200 kg a second, the sheer amount of ice and dust is such that scientists think that one, measly moon is the source of one of Saturn’s rings.
Most of it, however, falls back down to the surface. So, yes, aside from being super cold, there are snowdrifts on Enceladus that are more than 100 m deep, and it took millions of years for that kind of snow to accumulate.
So, cold AND snowy. Skip this one if you can, unless you fancy saving up for what would certainly be the ultimate ski weekend.
Pluto and Eris are a whisker warmer than absolute zero
If you, in your inexplicable quest to escape anything remotely resembling warmth, have made it as far as the outer reaches of the solar system, we hope you packed some longjohns.
Certainly this artist’s impression of the surface of the dwarf planet Pluto looks suitably frigid.
And when we say “frigid,” we mean, “Forty degrees above absolute zero,” or about -233C on a cold day.
Absolute zero has only ever been recreated in a lab, as far as we know, but it’s the theoretical point at which all atomic motion comes to a halt. So, super cold, is what we’re saying.
Want to know something even more chilling? Pluto isn’t even the coldest dwarf planet in the solar system(yes, dwarf planet. Yes, we know you were taught it was a full planet when you were a kid. Yes, we’re still mad about its cruel reclassification too).
That would be Eris, another dwarf planet, seen here in this artist’s impression:
Your average day on Eris lasts about a thousand years, but even with that gorgeous amount of sunlight hours, it’s not likely to get above -243C … ten degrees COLDER than Pluto, which puts it about thirty degrees above absolute zero – which, we remind you, is the theoretical coldest it can possibly get.
So, yeah, if those windchill warnings are getting you down, remember: It could be way worse.