That's where pure science meets commerce. The title of an article is intended to draw readers and unequivocal statements get more eyes than uncertainty.
A thought: Now I am wondering if the answer to Fermi is that the universe is only just now (or recently) becoming capable of making planets with enough elements for complex life? (Just came up with this in the thread about Venus' clouds and thought I should post it here too.)
One of the solutions to the Fermi Paradox is the idea that we are the first civilization in this galaxy. With the need for stars to build up the heavier elements needed to create long carbon chains. I have an issue with this, in that time moves a lot faster than most people realize. We are only 100 human lifetimes from Stonehenge. We went from advanced hunter-gatherer societies to space flight in the geologic blink of an eye. If we are 10,000 years behind everyone else, they must be so advanced that we are but ants. 100 years ago electricity was a luxury, we barely had flying machines, and health care was just starting to come into its own (Vaccines are about 100 years old, mass vaccination programs are only 60 years old). Space is big, very big. Other stars that can host planets like ours are far away and those planets are very hard to find. The James Webb Telescope will let us for the first time sample the atmospheres of exoplanets, and the TESS mission launching next week will find the targets to look at. I was listening to a telecast about TESS and they think that TESS will find 17K-20K exoplanets... we have verified just about 4K now. The question about are we alone? We will be getting closer to confirming that within the next 20 years. If we land on Europa? I hope we find DNA and bacteria. It's an exciting time to be a space nerd.
I have a hard time believing we could be the first. Perhaps one of the earliest? The more places we go poking around in our solar system, the more places we find that life could possibly exist. What if we find microbes all over our system, and what if we are all related? How could we ever figure out who came first?
Planets have been around for a while it seems. Now, imagine an earth-like planet, with liquid water and enough carbon, nitrogen, iron, and oxygen to get the ball rolling, but life in this theoretical world has a 50 million year head start from our planet. 50 million years ago is not that long in the timeframe of a 14 Billion year old universe. I love this idea, this line of questioning because it gets into chemistry, physics, deep time, philosophy, history, astronomy and always generates good discussions at events. I believe that there is life out there. It may even be looking up in our direction. But I doubt that there will be any contact with 'aliens' in my lifetime. I do think we will 100% find confirmed living bacteria, and maybe basic multi-celular life in places like Enceladus and Europa in my lifetime. Here is a curve ball for you, just something to think about. I hope that life looks exactly like life on earth. If we find living things out there in the solar system and it looks different than earth life? Then the concept of a Great filter gets really fucking terrifying. If life pops up on 3-4 places in a solar system, and we have no evidence of sentient life out there in space, maybe there is a filter we are approaching that no other living thing was able to break through. IF, however, all that life is the same amino acids and DNA as earth life, that starts to look like life started once in the solar system then spread through asteroid and comet impacts. We know life can survive in space and we know that rocks from the earth and Mars and the Asteroid Belt interact with each other over time. Either thought is both amazing and terrifying to contemplate.
I wonder if there are other elements which can take the place of phosphorus in our biology (or that of an alien species)? I know there are illnesses that are caused when our bodies take in certain elements and they take the place of others in some process, which works but isn't quite right.
http://periodictable.com/Properties/A/UniverseAbundance.v.log.html If I am understanding this table correctly, there is a whole lot more arsenic out there than phosphorus, so if biology can take a slightly different route, the lack of phosphorus is not necessarily as big of an issue as it might seem (to us who are dependent upon it)?