As far as life outside earth we are in the same situation scientifically as we are with the origin of earth life. The only evidence we have is a lack of evidence of any extraterrestrial life. (NASA paper with thesis
FACT A: THERE ARE NO EXTRATERRESTRIALS VISIBLE) We have all been inculcated, most visibly by Carl Sagan, with the "mediocrity concept". These arrogant anti-theists delight in saying "we are unremarkable, on an unremarkable planet". But thats simply not true by evidence and leads to the
Fermi Paradox. Using the scale of the
Principle of Mediocrity...
(1)"there are an estimated 200–400 billion stars in the Milky Way (2–4 × 1011) and 70 sextillion (7×1022) in the
observable universe."
(2) Mediocrity, plugged into the Drake Equation says the chances of humans being the only intelligent life are 2.5×10−24. In other words there must, by probability, be other life.
(3) the universe is ~13-14 billion years old. There are much older planets than ours. We have confirmed planets (Kepler 425B for instance) in habitable zones which are 1.5 billion years older than Earth and that is just what we have observed directly.
(4) a civilization which expanded into space at just 1% the speed of light would cover the galaxy in 20 million years...a minuscule drop in the bucket in the head start planets like Kepler 425b have over Earth...never mind accounting for the more ancient planets or the multitude of civilizations we have been told must exist...
link
This led Fermi to ask..."if these suppositions are true then where is everybody?". The last link I gave gives some interesting possibilities such as the
Great Filter but again that leaves us as remarkable for having survived it apparently alone...(unless that filter is in our future.)
Looks to me like past,present or future..here or elsewhere in the Universe..we are it.