Explanation:
Have you ever seen the planet Mercury?
Because
Mercury orbits so close to the Sun,
it never wanders far from the Sun in
Earth's sky.
If trailing the Sun,
Mercury will be visible
low on the horizon for only a short while
after sunset.
If leading the Sun, Mercury
will be visible only shortly before
sunrise.
So at certain times of the year an
informed skygazer with a little determination
can usually pick Mercury
out from a site with an unobscured horizon.
Above, a lot of determination has been combined
with a little
digital trickery to
show Mercury's successive positions during March of 2000.
Each picture was taken from the same location in Spain
when the Sun itself was 10 degrees below the
horizon and superposed
on the single most
photogenic sunset.
Mercury is
currently visible in the western sky
after sunset, but will disappear in the Sun's glare after a few days.
