OK, so its not little green men on Mars...or Titan...or anywhere else in the Solar System.
But what it is (being announced at a much hyped news conference today at 2PM by NASA) is the discovery of an entirely new "type" of life. All life (until now) from the smallest bacteria to you and me has used only the following chemicals in the makeup of its DNA--Carbon, Hydrogen, Nitrogen, Sulfur, Phosphorus and Oxygen. That's it. And its been across all life on earth in all its forms--until now.
Now, for the first time, a life form has been found to have swapped one of these core building blocks for something else. In the case to be announced today, Arsenic has been swapped for the Phosphorus in a particular bacteria, found thus far only in Mono Lake in California. Until now it was assumed that Phosphorus would be required for any life to arise--now we know that not to be the case.
Why this is important is that this finding would suggest that there are ways for life to arise under very different sets of circumstances that what we had previously assumed. No longer will scientists assume whole hosts of planets and moons are unsuitable to life simply because they are not similar in their chemical makeup to our home world. Additionally, the substitution of Arsenic for Phosphorus hints that other substitutions are possible, if not likely, and open up even more worlds for possible life to arise upon.
Included in these potential worlds are the numerous moons of Saturn and Jupiter, many of which had been ruled out for life due to what scientists had considered inhospitable conditions. Now it turns out...they may be hospitable after all.
So no...no little green men...but we (they) are getting closer every day.
When I was young I asked my father if he thought that we would have contact with "aliens" in his lifetime and he said that he believed that we would. Some 25 years later it still hasn't happened but I must say, with the advancements in our ability to "look" at worlds light years away and determine their general chemical makup and planetary conditions and now this development... I feel he will be proven right.
NASA News Conference and Announcement...