Astrobiology is mainstream Science, but String theory only emerging ‘Protoscience’
Astrobiology is to be seen as a complex of studies using scientific methods, taking from and contributing to the body of knowledge from several scientific disciplines, including meteoritics, extremeophiles, planetary (and exo-planetary) environments, space biology, hypervelocity impact…. If not before, it certainly came of age in 1996 on NASA’s announcement of evidence for life in a martian meteorite.
Origin-of-life studies are largely a separate scientific field; what Bandyopadhyay et al.
call Metabolism First and RNA World theories may have “serious defects” [limitations], but this does not characterise astrobiology as a whole.
Panspermia is an important part of astrobiology science, starting as a fruitful hypothesis that developed into a ‘good’ coherent theory – over many decades it has made predictions and stimulated experimental checks. It unifies themes, eg. apparent biomorphs in meteorites, space hardiness of microorganisms. It’s pretty secure in terms of transfer of life between solar system bodies, though not (yet) for interstellar
Philosophers of science need to recognise the criticisms of physicists that string theory is more a hunch than a ‘theory‘ (‘t Hooft) with its fundamental principles unknown, as is the mathematical language for framing it (Smolin). It’s a research
programme that could be fundamentally flawed (Woit). Insofar as science is what scientists do, string theory is protoscience, an area of scientific endeavor that’s largely conjecture. It’s not a ‘theory’ and suffers from some features of pseudo-science.
A final point is not to confuse string theory with Einstein’s General Relativity, developed into gravitational field theory, which indeed has “garnered huge
amounts of evidence in its favor”.
We need philosophers of science to explore why astrobiology and panspermia have low status within the wider science establishment – the latter being being sidelined even by such as bioastronomer Caleb Sharf – while protoscience as in the misnamed string ‘theory’ is revered.