Evening star., 1952-06-02
Astronomer Finds Clues
To Plant Life on Mars
Says Green Areas on PIonet
Probably Are Hordy Liehens

Probably Are Hardy Liehens
By Thomos R. Henry
Plant life probably exists on Mars.
Conditions on the neighbor planet are
such as to permit the growth Of ichens.
says DR.. Gerard p. Kuiper. professor Of
astronomy at the University of Chicago.
He has summarized all scientific evi-
dence for and against life on Mars in a
book, The Atmospheres Of Earth and
Planets. just issued by the University Of
Chicago.
If life did develop on the only two
planets in our solar system that are at
all suitable to sustain it, DR.. Kuiper
writes, it is tempting to conclude that.
after enough time has elapsed. it will
develop spontaneously wherever condi-
tions permit. Since planetary systems
are presumed to be very numerous, life
would then be no exception in the
universe"
Green Areas Probably Lichens.
Looked at through q telescope, the
surface of Mars contains green areas,
set of against bright orange areas which
astronomers conclude is desert. It Is
these green areas which may well be
fields Of lichens.
The green areas cover about third
Of Mars. The height of the lichens in
terms of what water is available for
their growth would vary from one-hun-
dredth of an inch to the thickness of q
sheet of paper.
Lichens are small plants related to
mushrooms and molds which grow in
combination with the simplest plants,
called algae. There are some 1900
kinds Of lichens known on earth.
These small plants have the ability
to withstand extremes Of heat and cold,
growing in places where the tempera-
ture is below freezing and in the Sahara
Desert. They can survive being immersed
in liquid air temperatures hundreds Of
degrees below zero.
It Is probable that lichens are the
only living things on earth which could
be tranSplanted to Mars and live there
under existing conditions. These plants
could readily grow on Mars because the
air contains fairly large amounts Of
carbon dioxide, necessary for their life.
DR.. Kuiper discovered the existence Of
carbon dioxide on Mars five years ago
through studies of the infra-red cor
heat spectrum Of the planet.
Temperature Change Not Total.
While the temperature of the planet
falls 12O degrees F. below zero during the
night, such temperatures would merely
temporarily inactivate the hchenS. Other
plants which contain q larger propor-
ton of water than do lichenS would
freeze during such temperatures.
Additional evidence to support lichen
growth theory is that the reflection spec
trum of Mars green areas differs greatly
from the reflection spectrum of higher
forms of plant life such as grass and
trees, and resembles that of hchens.
The color Of the green areas on Mars
changes with the seasons resembling
the color changes seen in lichens. The
colorS in the green areas are not those
displayed by non-living substances like
crystals.
Furthermore, there must be some
aspects of life in these green areas to
account for their regeneration after
being buried by the yellow dust clouds
which often swirl around Mars.
Furthermore. all the evidence indi-
Gates that the wfitish areas at the
poles of the planet are ice rather than
frozen carbon dioxide-dry ice. Evapo-
rating. this ice would provide water in
the atmosphere from which the plants
could absorb their limited needs of
moisture.
Conditions Were Favorable to Life.
There is other. but less direct, evil
dence Of life on Mars. The planet
has had as much time for life to evolve
as the earth has. The evidence also
indicates that more favorable condi-
tions for the development of life ex-
listed earlier in the history of Mars. with
warmer and more humid temperatures.
The negative evidence is far less
strong. The range Of temperatures on
the planet, while extreme. Is not too
great for lichens to exist And while
the planets might be exposed to more
ultraviolet radiation than on earth, be-
cause the atmosphere Of Mars is thin
ner, this would not be too great to for.
bid life.
The only drawback to a belief in
life on Mars is the assumption that
developments on Mars paralleled those
on the earth. On the other hand, DR..
Kuiper believes there Is no great reason
for assuming otherwise.
Mars Is the only other planet In our
solar system which is capable Of sus-
tanning any of the forms of life as we
know them. Venus is rich in carbon
dioxide but lacks oxygen and water.
The giant outer planets, Jupiter and
Saturn, have atmospheres rich in poi
sonous gases, and temperatures plum
melting to hundreds of degrees below
zero.