From ice volcanoes to hundred-metre snowdrifts: Seven frigid planets
Sunday, January 5, 2014, 5:21 PM -
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.
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?