how not to approach astrobiology
Panspermia is a hypothesis of how life might have hitchhiked to Earth. It's not meant to explain how life actually began.
Normally, when it comes to the concept of panspermia, I'd like to call myself open-minded. Having alien bugs or bacteria travel across space and landing on potentially habitable worlds isn't nearly as far fetched as it may seem according to a number of studies and experiments. Additionally, we've known for a long time that all the comets and meteors that hit our planet on a regular basis during its youth were the closest thing to chemistry kits for kick starting life, delivering water, amino acids and organic compounds with every impact. So the idea is scientifically sound, but one attempt at advocating it almost made me do a spit take across my keyboard as potentially great science was drowned out by a statement that goes against all known biology and physics.
The news editor at Cosmic Ancestry was doing a little write-up about the puzzling discovery of seemingly old galaxies in distant space. Since looking into the depths of space is also like looking back in time, this would mean that the galaxies aged prematurely. This is certainly an interesting anomaly that needs to be explained, but it's hard to see the link between these results and the origin of life. And this is when this little gem reared its ugly head, mixing creationism and pseudoscience in a manner worthy of Answers in Genesis…
Most darwinists know little about the big bang, but rely on it to mandate that life must originate. In cosmic ancestry life never originates and must come from the infinite past.
Wait, what?! We have to throw out modern cosmology to accommodate panspermia? Since when? And aren't we left with the same infinite reductionism problem we find in religion? Life had to come from somewhere, so just pushing it back to the ancient past and ignoring what the other sciences have to say about the universe to make it plausible, doesn't work. Wasn't the whole point that life gets started on one planet and eventually, due to chance, cross-pollinates other worlds and the evolution takes off in its new home? And speaking of that, do we really need to invoke an anti-evolution epithet favored by creationists? Isn't alien life hitchhiking from world to world supposed to evolve in its new home, not just arrive as a pre-assembled ecosphere?
Here's the bottom line. Panspermia can't be the answer to the origin of life in general. It can explain how living things arose on a particular planet and is at best, an intriguing and potentially profound part of a much bigger puzzle. Whether it got there through incredibly tough microorganisms that made it to other worlds by everyday events, or as forward contamination by alien explorers surveying potentially habitable worlds, it will never give us the ultimate answer of how life arose. We can only find out with biochemical experiments and research. To use alien bacteria as the ultimate answer to the biggest question of biology is a religious tenant, not a serious scientific statement by any stretch of the imagination.
