Sky and Telescope - June 2018 - 67

MIZ A R A ND A LCOR: A K IR A FUJII; CO M A STA R CLUSTER: N ASA / DON A LD R. PE T TIT; A LBIREO: STEFA N BINNE WIES / JOSEF PÖPSEL / CA PELL A OBSERVATORY; FIGURE: LE A H TISCIONE / S&T; RING NEBUL A: N ASA / ESA / C. ROBERT O'DELL ( VA NDERBILT UNIV ERSIT Y ); CAT'S E Y E NEBUL A: NORDIC OPTICA L
TELESCOPE / RO M A NO CORR A DI (ISA AC NE W TON G ROUP OF TELESCOPES, SPAIN)

american cultures were devising astronomical calendars of
stunning accuracy. To see light that has traveled since the last
centuries BC, seek out M57, the Ring Nebula, in Lyra. From
Earth, M57 sits only a little more than 6° from Vega, but at
2,300 light-years, it's almost 100 times as distant.
Our next stop is another planetary nebula, NGC 6543
(Caldwell 6), the Cat's Eye Nebula in Draco, the Dragon. The
Cat's Eye lies 3,600 light-years away, and its light comes to
us from the Bronze Age. One of the most impressive astronomical artifacts to survive from that time is a sky disk from
Nebra in Germany. A bronze disk 12 inches in diameter and
inlaid with gold, the Nebra sky disk depicts the Sun, the
Moon, and a star cluster (probably the Pleiades), and also
marks the solstices.
For our next step we will voyage far to the south, both
geographically and celestially. M8, the Lagoon Nebula in Sagittarius, the Archer, is a stellar nursery, and one of only two
star-forming regions visible to the naked eye (the other is the
Orion Nebula, M42). The light we see now left 4,100 years
ago, when the Great Ziggurat of Ur was being constructed in
Mesopotamia (modern-day Iraq). The ziggurat was a temple
to the moon god Nanna, and it embodies the importance of
astronomical phenomena to the ancient Sumerians.
Sweep 21° northwest from M8 and look 2,100 light-years
farther out, to M11, the Wild Duck Cluster, in the constellation Scutum, the Shield. At 6,200 light-years from Earth,
M11 is one of the more
distant
open sta
star cclusters
o ed
sta t ope
uste s in tthee
Messier catalog. Its light corresponds in
age with what may be the oldest star
map yet discovered, the Fuxi star
map, from a Neolithic
hic tomb in
Henan, China.
Greece, Central America, Germany, Mesopopo-

q CALENDARS AND CHARTS Light from these planetary nebulae embarked on its cosmic voyage around the time the Mayans were performing complex calendrical calculations and peoples of the Bronze Age were
crafting the first star charts. Your binoculars or telescope won't reveal
this level of detail, but bear these images in your mind while you observe.

tamia, China - ancient cultures across
the globe not only observed the
heavens, they consecrated
that knowledge in temples,
tombs, calendars, and
even computers. We
pause now at the edge
of a gulf, both in the
sky and in our own
past. Until now,
we've been observing stars, clusters,
and nebulae in the
adjacent spiral arms
of the Milky Way.
It's time to step out
into the galactic halo,
and out of recorded
human history.

Cat's Eye
Nebula

Ring Nebula

Albireo

TUMULTUOUS TIMES
Light from the gloriously colored
Ligh
double star Albireo left at around
doub
time the heliocentric model of
the tim
the sol
solar system was replacing the
familiar geocentric model, Tycho
fami
Brahe took Johannes Kepler under
wing, and Galileo was soon to
his w
point his telescope skyward.
p
sk yandtelescope.com * J U N E 2 018

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Sky and Telescope - June 2018

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