The hottest and coldest waters on Earth

Earth is about three quarters covered in water. So.... why is it called 'Earth'? Does that make sense to anyone?

Never mind.

The point is that water will play some pretty bizarre tricks under the right circumstances......

The coldest:Don Juan Pond.

Water, as I learned in high school, is supposed to freeze at zero degrees Celsius. So Don Juan pond in Antarctica poses a bit of a problem for my high school science course, as it's been known to stay liquid down to minus thirty degrees Celsius.

 

Alien waters: Don Juan Pond, which is almost literally a slice of Mars on Earth

Why? Well as well as being stubborn, Don Juan pond is the saltiest body of water in the world, and the salts act as a kind of natural antifreeze. In this case they're so effective that, in theory, if you moved Don Juan pond to Mars it would stay liquid.....

The Hottest: Hydrothermal vents.

I also learned that water is supposed to boil at one hundred degrees Celsius. However, no told the deep ocean about this, and the churning water shooting out of the hydrothermal vents down there has been measured at three hundred degrees Celsius - and still stubbornly liquid.

 

The Black Smoke: The 'Smoke coming out of this vent is actually polluted water, still liquid at over three times its normal boiling temperature....

In this case it's the incredible pressure of the ocean above that forces the water to stay liquid, well beyond what we'd think of as its normal limits. And while Don Juan might be a lake well at home on Mars, the things growing around hydrothermal vents look like they've come from a lot further away than that.....

 

Above: The giant tube worms (about as big as your arm) growing near a hydrothermal vent, living almost entirely off its energy.

So; high school physics nil, weird-ass reality two. Which is not to say high school physics was totally wrong. It's just that the 'rules' will always do something strange if you push them far enough.....