My own general view of the Fermi paradox (with the universe so big aliens should have visited by now) is that there is no reason to think that we are that interesting to need a visit instead of remote observation and if they visited more than 5000 years ago then we forgot or were not around.
Now science that relates to the Fermi paradox brings word that a deficiency of oxygen and the heavy metal molybdenum in the ancient deep ocean may have delayed the evolution of animal life on Earth for nearly 2 billion years.
So better understanding of chemical conditions in planets could show that it is more difficult and rare to get up to complex lifeforms.
NASA's Cassini spacecraft tasted and sampled a surprising organic brew erupting in geyser-like fashion from Saturn's moon Enceladus during a close flyby on March 12. Scientists are amazed that this tiny moon is so active, "hot" and brimming with water vapor and organic chemicals.
There is the recent discovery of another hidden ocean in the solar system, this one underneath Titan's crust.
If confirmed, Titan would be the fourth moon in the solar system thought to contain such an internal water ocean, joining Jupiter's satellites Ganymede, Callisto and Europa.
Europa's ocean pic by Nasa
Callisto's core and ocean by Nasa
Jupiter's second largest moon, Callisto, may have a liquid ocean tucked under its icy, cratered crust, according to scientists studying data gathered by NASA's Galileo spacecraft.
Nasa vision of the inside of Ganymede, another moon of Jupiter
Enceladus, sixth largest moon of Saturn has water ice on its surface and water geysers. There also could be a lot of ice on Mars and the moon and possibly some underground liquid water on Mars.