I assume they measured the temperature and atmospheric pressure at the rover and have done the calculations to make sure it's actually <i>possible</i> that this was frozen H20 that sublimed? NASA is pretty smart, right?<p>At least here on Earth I would expect that a solid white material that sublimed was C02. Of course Mars is very different temperature and atmosphere-wise.
In other words, news broke out on twitter 2 1/2 years after ice was found on mars.<p><a href="http://news.bbc.co.uk/2/hi/science/nature/4479612.stm" rel="nofollow">http://news.bbc.co.uk/2/hi/science/nature/4479612.stm</a>
Why the second half of the title? I could give it a <i></i><i></i> less if it was "broken" by Digg or Twitter or Slashdot or email - the only thing that matters is whether there is ice or not on Mars. You don't see CNN headlines suffixed with "as AP told us" or "and Reuters had it first!" etc.