117
See also: Observing Saturn’s rings 65 ■ Analyzing starlight 113 ■
Life on other planets 228–35B
y the mid-19th century,
scientists were increasingly
speculating about the
possibility of life on Mars, which
had been found to have certain
similarities to Earth, including ice
caps, a similar length of day, and an
axial tilt that meant it experienced
seasons. However, it had also been
found that it did not rain on Mars.
Between 1877 and 1890, Italian
astronomer Giovanni Schiaparelli
carried out a series of detailed
observations of Mars to produce
a map of the planet’s surface.Schiaparelli described various dark
areas as “seas” and lighter areas
as “continents.” He also portrayed
what seemed to him to be a
network of long, dark, straight lines,
or streaks, crisscrossing Mars’s
equatorial regions. In his book Life
on Mars, Schiaparelli suggested
that, in the absence of rain, these
channels might be the mechanism
by which water was transported
across the dry surface of the
planet to allow life to exist there.
In the following years, many
eminent scientists, including
American astronomer Percival
Lowell, speculated that these
dark lines were irrigation canals
constructed by intelligent beings
on Mars. However, others could
not see the channels at all when
they looked for them—and by 1909,
observations with telescopes of
higher resolution had confirmed that
the Martian canals did not exist. ■THE RISE OF ASTROPHYSICS
MARS IS TRAVERSED
BY A DENSE NETWORK
OF CHANNELS
MAPPING MARS’S SURFACE
IN CONTEXT
KEY ASTRONOMER
Giovanni Schiaparelli
(1835 –1910)
BEFORE
1858 Angelo Secchi first uses
the word canali (channels) in
connection with Mars.
AFTER
1897 Italian astronomer
Vincenzo Cerulli theorizes that
the Martian canals are just an
optical illusion.
1906 A book by American
astronomer Percival Lowell,
Mars and Its Canals, promotes
the idea that there may be
artificial canals on Mars,
built by intelligent beings.
1909 Photographs of Mars
taken at the new Baillaud
dome at the Pic du Midi
observatory in France discredit
the Martian canals theory.
1960s NASA’s Mariner flyby
missions fail to capture any
images of the canals or find
any evidence of them.
Schiaparelli’s 1888 atlas of Mars
shows land, seas, and a network of
straight channels. Here, the south
pole is shown at the top.