exactly-in the 1960's when carl sagan talked about

exactly-in the 1960's when carl sagan talked about billions of possible planets w life there were only 2 known required parameters for life on a planet-the only place life can originate.

now many hundreds of such parameters are known to exist and the probability of even one planet meeting everyone of those parameters is 1 in 10 followed by probably millions of zeros.
astrophysicists determined that the probability for humanity to arise from bacteria in 10 billion years is 10 to the minus 24 million zeros. Man appeared suddenly... scientists usually consider something that has less than 1 chance in 10 followed by 50-100 zeros as a practical impossibility.

just 2 of those parameters:
1) for stars and chemical elements necessary for life the cosmic mass density had to be tuned to 1 part in 10 followed by 60 zeros-

2)the cosmic dark energy density had to be tuned to at least 1 part in 10 followed by 120 zeros. this is equivalent to winning the california lottery 150000 consecutive times w just one ticket each time.

but we've brainwashed by the admittedly otherwise enjoyable shows of star trek etc. The maximum speed attainable by spaceships-physical laws which cannot be overcome by technology- is ca 1% of the speed of light (-not the ca 525? times the speed of light of warp 5- and the paltry 25000 mph of manned missions so far is far below that-so we're stuck in this solar system re manned space travel-and so would any other species be in their solar system.
if the mass were slightly greater only dark holes and neutron stars would exist-if less- stars could not form -just one of many hundreds of parameters now becoming known (and somehow rejected? by those whose preconceived ideas dont comport w this new science). See astrophysicist Hugh Ross's books.