Stuff I've been seeing lately about space—current (or sort of current) estimates of this or that—has me feeling amazed and baffled and happily minute.
Apparently, and this is based only on a sampling of stars in the Milky Way, there could be 17 billion Earth-sized planets
in our galaxy alone. Recent (?) estimates based on the Hubble Extreme Deep Field
(more sensitive than the Hubble Ultra Deep Field) tell us there could be more than 175 billion galaxies in the universe. (Better technology will almost certainly require us to bump up those estimates.)
If we assume (because, why not?) that the distribution of Earth-sized planets is similar in all those other galaxies, that means the universe is home to 2,975,000,000,000,000,000,000 Earth-sized planets.
means if you tallied up one of the universe's Earth-sized planets every second, it would take you something like 94 trillion years to count them all. (And that's coming up on 7,000 times longer than the universe has existed [13.75 billion years].)