[Red Badger]

Mars is a desert planet. Credit: NASA/JPL/Malin Space Science Systems

The habitable zone in our solar system, compared to the habitable zone for the red dwarf star Gleise 581. Credit: ESO

Morocco dune at sunrise. Are desert worlds the more common type of habitable planet in the galaxy? Credit: wikicommons / Matanya

[Red Badger]

The Spice must flow..........................

[sniper63]

Mau’ Dib, save us...............

[GeronL]

As long as they aren’t overtaxed by the elite giant worms

[edcoil]

I hate the worms - don’t you hate the worms - Beetle Juice.

[Graybeard58]

if they are too close, steam builds up in their atmospheres, trapping heat that vaporizes still more water, leading to a runaway greenhouse effect that boils all the oceans off the planet, as apparently happened on Venus

If Venus lost its water by being to close to the sun, how did it have water to begin with? Was it at one time, farther from the sun?

[cripplecreek]

The possibilities are pretty much endless.

A while back I was reading about the theoretical possibilities of habitable zones on tidally locked planets.

[17th Miss Regt]

That looks like whipped cream on the top of the Mars. Does that mean it is also a dessert planet?

[NonValueAdded]

Time to start that stillsuit factory

[darth]

They look like seashells to me:

http://www.amazon.com/Fossil-Hunters-Guide-Mars/dp/1450720633/ref=sr_1_1?s=books&ie=UTF8&qid=1311616656&sr=1-1

Years ago I met the NASA scientists who wrote the paper on the Allen Hills meteorite. That rock had the isotopic signature of Mars and the bacteria fossils were almost exactly like certain bacteria on Earth. More evidence that Mars probably still has at least microbes in hot springs. There are extremophiles on Earth that would do just fine in an acid Martian hot spring.

I also offer bets on Europa. We might even find fish under the ice.

[Boogieman]

“as recently as 1 billion years ago”

Oh, it was that recent, eh? We just missed it :P

[Texas Songwriter]

Physorg.com....it reads like a Marvel Comic Book writer. Let’s pretend...make up some stuff and pretend it could represent science.

[exDemMom]

I always wonder how anyone can determine what the necessary parameters would be for life to exist on another planet. Our sample size of habitable planets is 1. That’s hardly a sufficient sample size from which to make any generalizations about what is necessary for life to exist.

[justa-hairyape]

They seem to be forgetting an important step. How do you get all that oxygen into the atmosphere ? It required a whole lot of biological life on Aqua Planet Earth to get all that CO2 converted into O. And those biological processes required a whole lot of water.