It is wonders of the universe such as these which got me hooked on physics many years ago, particularly astronomical events that we can observe relatively simply (a telescope with a solar filter will do).
Although I studied the smallest known constituents of matter (quarks and gluons) when I was a proper physicists (before training as a patent attorney), it is knowledge of this small scale which helps us explain how the universe appears to us on a large scale.
So sit back in wonder to watch the transit of Mercury, observing two celestial bodies millions of miles away lining up in this way.
Skywatchers across the globe are observing Mercury transit the Sun, the little planet's third such pass of 14 it will make this century. Mercury's sojourn between Earth and our star lasts from 11:12 until 18:42 GMT. It will not make another transit until 2019 and then 2032.