WWW.ASTRONOMY.COM 61
objects — the most by any discoverer
— through a variety of telescopes.
Because all the instruments he used were
small and of questionable quality, he
found only large, bright objects. This
works to the advantage of today’s observ-
ers, because even a medium-sized mod-
ern scope can really make these big
objects pop.
Running the marathon
The 109 targets in Messier’s catalog
are not distributed evenly across the
sky. That’s good, because if they were,
there would never be a time when you
could see them all during a single night.
Instead, one or more would always be
too close to the Sun. Sagittarius holds 15
of the objects, the most of any constella-
tion. Virgo is next (11), followed by Coma
Berenices (eight), and Ophiuchus and
Ursa Major (seven each).
The most important point about this
uneven distribution is that none of the
targets resides in western Aquarius or
eastern Pisces. So, when the Sun passes
through that area in its yearly apparent
trip through the constellations of the
zodiac, it burns far from any M object.
That means observers have a chance to
see them all in a single night.
Years ago, contributing editor Tom
Polakis calculated the window of oppor-
tunity for a complete Messier marathon.
He defined the beginning of the observ-
ing window as the date when globular
cluster M30 in Capricornus is high
enough to spot in a dark sky. Working The Blackeye Galaxy (M64) in Coma Berenices is an easy catch through a small scope.
The Trifid Nebula (M20) in Sagittarius lies low in the sky for many observers, but it’s well worth finding.ABOVE: The Hercules Cluster (M13) is a favorite
target for amateur astronomers.
LEFT: The Southern Whirlpool Galaxy (M83) in
Hydra is one of the finest barred spirals in the sky.