For centuries,
people created their ideas and visions about Mars. Some predictions
finally came true, even more did not. Let’s take a look at the
accuracy of famous (and infamous) historical ideas about the Red
Planet.
The
moons of Mars
Idea:
The
existence of two Martian moons was predicted around 1610 by Johannes
Kepler. His prediction wasn’t based on sound scientific
principles, but his ideas were so influential that the two moons were
discussed in works of fiction. Jonathan Swift referred to the two
moons in his Gulliver’s
Travels (1726) where
astronomers in a fictional kingdom called Laputa are described as
having discovered two Martian moons orbiting at distances of three
and five Martian diameters, with orbital periods of 10 and 21.5
hours.
Reality:
Two
Martian moons, Phobos and Deimos, were discovered by Asaph Hall in
1877. The actual orbital distances and periods of Phobos and Deimos
are respectively 1.4 and 3.5 Martian diameters and 7.6 and 30.3
hours.
Martian
canals
Idea:
In
the late 19th Century, Italian astronomer Giovanni Schiaparelli
observed apparent linear features covering Mars like a net. He called
them “canali” (Italian: “channels”).
Fascinated by this, the US businessman Percival Lowell built an
observatory and started studying these “canals”,
convinced that they were built by Martians to irrigate the planet’s
deserts. Faith in this Martian civilization was so huge that Lowell’s
canal-strewn map of Mars was accepted by many scientists and the
general public.
Reality:
In
1964 NASA’s Mariner 4 returned images of a lifeless desert
landscape that was completely devoid of “canals”, ending
the controversy. Still, the Martian “canals” is one of
the most embarrassing episodes in astronomical history.
Valles
Marineris
Idea:
Valles
Marineris (Latin for Mariner Valleys), the “Grand Canyon on
Mars,” is actually a large system of canyons that was
originally considered as a part of Martian Canals.
Reality:
After
the “canals” idea was denied, there have been many
hypotheses about what formed Valles Marineris: water, magma, or
carbon dioxide glaciers? Today, scientists suppose that the canyon
system was formed mostly by rifting of crust as it got stretched.
The
“face” on Mars
Idea:
A
strange-looking humanoid “face” was identified in images
of the Cydonia region returned by NASA’s Viking 2 spacecraft in
1976. Could the “face” have been constructed in the
remote past by a Martian civilization?
Reality:
By
combining high-resolution images from ESA’s Mars Express probe
and NASA’s Mars Global Surveyor, it has been possible to create
a three-dimensional representation of the “face”.
Clearly, the simulacrum was produced by the play of light and shadows
on a small Martian hill—simply an optical illusion.
The
same situation occurred with the “Inca City”, a set of
intersecting, rectilinear ridges in the south polar region of Mars
that superficially looks artificial. Most investigators think they
are sand dunes, while others consider them to have been formed by
injection of magma into subsurface cracks that subsequently hardened
and were then exposed at the surface and subjected to wind erosion.
Water
on Mars
Idea:
Water
indicates life, so the search for water on Mars is inextricably
linked to the search for life. In 2008, the NASA’s Phoenix
lander’s “selfie” showed drops of liquid water
clinging to its titanium legs. This gave hope to the existence of
liquid water in the top layers of the Martian soil.
Reality:
With
the exception of the lowest elevations (and then, just for a few
hours) the low atmospheric pressure and temperature rules out the
existence of liquid water in a stable form at the Martian surface.
Phoenix’s observations separates scientists into two groups:
the salt water with perchlorates theory and the ice sublimation
theory. Both are pretty right, although almost all water on Mars
exists as ice. Now, there are ambitious projects intended to release
water from the ice polar caps by melting them with orbital mirrors,
or solar sails, probably able to reflect solar energy and redirect it
down to the polar areas.
Terrestrial
life came from Mars
Idea:
Could
life on Earth have started on Mars, arriving at our planet on
meteorites blasted from the Martian surface? One argument is that the
oxidized mineral form of molybdenum, which may have been crucial to
the origin of life, could only have been available on the surface of
Mars and not on Earth at the time life first began.
Reality:
Prof.
Steven Benner (Westheimer Institute for Science and Technology)
supposes that the surface of Earth had very little molybdenum and
boron—elements that seem able to control the propensity
of organic materials to turn into tar (the “tar
paradox”)—but Mars did. In addition, it’s suggested
that life would have struggled to start on the early Earth because it
was totally covered by water, which is corrosive to the important
life-molecule RNA (the “water paradox”. Water on Mars
covered
much smaller areas than on early Earth. This seems to be
building up to the idea that we are actually all Martians!
Terraforming
Idea:
Terraforming
is the idea of modifying a planet’s atmosphere, temperature,
etc. to make it Earth-like and human-friendly. The term was suggested
by the sci-fi writer Jack Williamson. “Space developers”
from Inspiration Mars Foundation have already chosen a place—Candor
Chasma in Valles Marineris—to implement their plan for building
the habitat using local materials. This called the Mars Homestead
Project.
Reality:
Such
a project would be extremely bold owing to the number of variables
involved in terraforming the Martian environment. The start,
according to the Inspiration Mars Foundation’s estimations,
will be possible no earlier than 2150. So stay tuned! However,
besides the technical side, there are major legal and ethical
problems associated with possible Mars colonization. Scientists ask
if it is really ethical to do this to any planet, because this can be
a one-way process of destroying it forever.
Svetlana
Zernes is a technical editor from Atlanta, GA, born and raised in
Russia. She earned her
Master’s degree in engineering in Europe and then studied
online at Harvard
University and University of California, Berkeley. Her areas of
expertise include technology, innovation, research and engineering
ethics, history of science, and futurology.
