Amazing how people can decide in an instant about something a few million miles away on a distant planet that they essentially know nothing about! My, the presumptuousness of the human ego!

Indeed - that was rather what I thought when I saw that website. The presumptuousness of those people's egos in thinking they've spotted this, when the NASA teams who are going over the photos centimetre by centimetre every day haven't done so. Either that, or the presumptuousness of them thinking that they're the only ones to have spotted the massive government conspiracy to conceal the truth from the world.

The presumption that they're seashells requires three major suppositions:-

1) There were once large bodies of liquid water on Mars.

2) Life evolved to a sufficiently high level within those bodies of water as to have produced fair-sized predators, because that's the reason these things have evolved shells on Earth.

3) There is no alternative source which would produce objects this shape.

Now the first one is a fairly well-known hypothesis, although short on evidence. The second is pure conjecture, unsupported by any evidence. These photos are *not* evidence, as they are so blurred and lacking in resolution that they could be anything at all (hence point three). And the third presumption is clearly wrong, because there are many things that they could be instead. The "wafer thinness" is completely consistent with a bubble in volcanic rock. The "whelk shell" could easily be two separate rocks close together, one rounded and one straight. And the third "shell" doesn't look anything like a shell to me.

The problem is that humans have a built-in need to find patterns in things, even when those patterns are merely a random element that just happens to have formed a particular shape. Saying "that cloud looks like a crocodile" is fine. Suggesting that it actually *is* an airborne crocodile may be taking things a bit too far...

Graham.