Scientists have estimated that a whopping 92 per cent of "Earth-like" planets have yet to be born, and inhabitants of such worlds in the far-distant future will be "largely clueless as to how or if the universe began and evolved".
Those are the conclusions of a study of Hubble Space Telescope and Kepler space observatory data by boffins from the Space Telescope Science Institute (STScI) in Maryland.
Kepler has already shown that "Earth-sized planets in a star's habitable zone, the perfect distance that could allow water to pool on the surface, are ubiquitous in our galaxy".
According to STScI, there are around 1 billion such bodies in the Milky Way alone. Multiply that by around 100 billion galaxies in the "observable universe", and you get an awful lot of potentially inhabited real estate.
While our own galaxy has used up a good whack of the gas required for star and subsequent planet formation, there's still masses of potential for future activity, particularly in dwarf galaxies and giant galaxy clusters.
The STScI scientists note: "The data show that the universe was making stars at a fast rate 10 billion years ago, but the fraction of the universe's hydrogen and helium gas that was involved was very low. Today, star birth is happening at a much slower rate than long ago, but there is so much leftover gas available that the universe will keep cooking up stars and planets for a very long time to come."
We know all this because our own ball of rock formed early enough in universal history for us to gather "observational evidence for the big bang and cosmic evolution, encoded in light and other electromagnetic radiation".
One trillion years from now, this evidence will have disappeared "due to the runaway expansion of space". That'll leave future beings speculating blindly about their origins for roughly another 99 trillion years, until the last star finally flickers out. ®