Thought Experiment...

Imagine the planet Earth.  Now imagine all the water on the planet – the oceans, rivers, lakes, snow, ice, groundwater, water in plants and animals, water vapor in the atmosphere – every last molecule of good old H2O.  Now imagine all that water gathered into a sphere.  How big would that sphere be?  Got it pictured, mentally?

Click here for the answer.  I was off by about 50%...

More Evidence for Liquid Water on Mars...

And the evidence comes via the plucky Mars rover “Opportunity”, currently exploring the Endeavour Crater.  It's now eight years into it's 90 day mission...

Ice: the Multi-Phasic Solid...

Plain old water ice is far more complex than you might think.  Click the figure at right for a phase diagram (of pressure vs. temperature) for that most familiar of substances...

Water in the Desert...

The roads we travelled yesterday are basically in the desert, and usually we don't see a single drop of water.  But yesterday many of the intermittent streams were running, in some cases strongly.  These photos are of a particularly pretty stream near where our road crossed it.  It was very pleasant to walk around the cold, splashing stream right in the middle of the warm desert.  Debbie stayed up on the road, as she doesn't like the idea of falling into the stream :-) ...