Water on Mars? Maybe not

What looks like the effects of liquid water on the surface of Mars may just be shifting sands that mimic liquid activity. Nothing so far proves that Mars is completely dry, or that there was no liquid water in the planet's past, but new experiments show that what has been observed so far could be just a 'trick' of nature.

Read more at Scientific American.

I don't understand why everyone is so crazy about water. Where's the connection between water and life ? It only happens to be what we know, but couldn't life be based on, say, silicon and ammonia instead of carbon and water ? Phosphorus and hydrogen fluoride ? Sulphur and carbon dioxide ?

You make a perfectly valid point, free::zombie. The presence of water on other planets may be an indication of life as we know it on Earth, or very similar, but we cannot rule out that life can be also based on other elements. Titan, Saturn's largest satellite, has an atmosphere essentially composed of methane, and even lakes of liquid methane, and it isn't impossible that life has also arisen there. Thanks for a very good comment.

Said By Thomas

You make a perfectly valid point, free::zombie. The presence of water on other planets may be an indication of life as we know it on Earth, or very similar, but we cannot rule out that life can be also based on other elements. Titan, Saturn's largest satellite, has an atmosphere essentially composed of methane, and even lakes of liquid methane, and it isn't impossible that life has also arisen there. Thanks for a very good comment.

It should be noted that any such life would be very very stinky.

It's true that other life may very well thrive in other conditions. Though so far we've found that life is very dependant on water and the functions it plays in a biological sense, and no water ever? I thought those big ice caps down at the poles was pretty good indication that there was water at one point on the planet.

Well, Mars has had what the scientists call a "wet period" between 4.5 billion and 3.7 billion years ago. It is possible that life has appeared then, and gone extinct due to the harsher conditions and evaporation of the water. Or maybe it evolved to face a new environment, who knows?

There's a recent and relevant article in the New Scientist about Mars's "wet" past: "Surging groundwater solves Martian \'evaporite\' mystery"