Download Mars - Montana State University Extended University

Astrobiology in the Classroom
NASA – CERES Project –http://btc.montana.edu/ceres
Montana State University
Preliminary Edition
“Microbial Zoo”
In this activity, students will explore the extreme conditions life is known to
exist in on our own planet. They will see that life can exist in a variety of
environments, broadening the prospects for life to exist elsewhere in the
universe. As humankind begins to look for life among the stars, it is critical
to understand the variety of conditions in which microbial life is found, so
that it will be easier to identify other worlds where it might exist. These
activities involve students in broadening their criteria for life by examining
those extreme environments on Earth, then looking at how those lifeforms
could exist on other known worlds within our solar system.
Part I – Exploration:
Living in a Microbial Zoo
1. Describe an environment on Earth that would not allow any form of life to exist.
List specific examples, and explain why these environments cannot support life.
2. Circle areas on the map of the world below that correspond to places on the Earth
having conditions that prohibit life.
3. Get together with a partner. Compare and discuss your responses to the previous
questions. Answering questions A and B below. Then use a different colored
pencil or pen to note any changes you would make in questions 1 or 2.
A. Are there any of your partners’ examples you would like to add to your
own, or vice versa?
B. Are there any that you would like to eliminate from your list?
Australiait was
4. After surveying a large number of college and high school aged students,
discovered that the three most common environments listed as being unable to
support life were (1) environments in which there is no oxygen, (2) environments
of extreme temperature (too hot/too cold), and (3) environments without access to
water.
A. Did you or your partner include any of these
environments?
Antarctica
B. If you didn’t, do you feel that you should have? Explain why or why not.
5. Scientists are currently searching for life on other planets and moons both inside
and outside our solar system. What types of life form do you think they are most
likely to find (1) animals, (2) plants or (3) microorganisms? Explain your
reasoning.
Part II – Concept Introduction:
With the growing interest and of the new multi-disciplinary science of astrobiology,
there has been an increase in funding for research projects investigating life forms
living in extreme environments on Earth. The term extreme environment is meant to
describe any environment that is extreme with respect to humans. As a result of this
research, we are finding that life exists in virtually every environment on Earth.
However, most of this life is in the form of microorganisms. Microbes that thrive in
extreme environments are lumped together under the generic name of extremophiles.
Extremophiles can be further classified according to the environments in which they
live. Examples of specific extremophiles are thermophiles, psychrophiles,
acidophiles, alkalophiles, barophiles, xerophiles, halophiles, and anaerobes. Your
teacher will now show you a Power point slide show introducing you to these
microorganisms. Get a blank chart of extremophiles to help you take notes during the
presentation.
1.
Now that you have seen the presentation, refer back to the environments listed in
problem 4.
Do you think that any of these environments actually present conditions too
extreme for life to exist?
2. Based on your responses to problem 6, what is the one environmental condition
that all life needs to survive on Earth?
Part III – Concept Application:
1. You will now receive a data sheet listing some extreme environments in our solar
system. What is it about each of these environments that makes them extreme?
a. Mars
b. Venus
c. Europa
d. Titan
e. Io
2. If you were searching for life on the planets/moons listed on your data sheet, what
types of extremophiles might you find? Explain your reasoning.
f. Mars
g. Venus
h. Europa
i. Titan
j. Io
3. Which planet/moon do you feel is most likely or able to support life? Explain
your reasoning in detail.
Extremophiles
NAME
Likes
Hates
Lives
Info
Organisms
Thermophiles
Psychrophiles
Acidophiles
Alkalophiles
Barophiles
Xerophiles
Halophiles
Anaerobes
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Montana State University
NASA CERES Project – http://btc.montana.edu/ceres
Preliminary Edition
More Extreme Environments
For comparisons sake:
Earth atmosphere: 78% nitrogen, 21% oxygen, 1% argon, and 0.03% carbon
dioxide
Earth temperature: 288K
Titan (moon of Saturn)
Mars
-thin and unbreathable
atmosphere
-atmosphere contains 95%
carbon dioxide, 3% nitrogen,
1.5% argon, trace amounts of
water, and no oxygen or ozone
-temperatures range from –125oC
to 25oC (223K)
-some rocks are basalt (volcanic
lava, as in Hawaii)
-polar ice caps made of CO2 ice
with possible water ice beneath
Venus
-extremely high atmospheric
pressure
-atmosphere contains 96.5%
carbon dioxide, 3.5% nitrogen
-little to no water
-sulfuric acid rain
-mean surface
temperature of 740 K (daytime
and nighttime)
Europa (moon of Jupiter)
-icy surface
-possible water oceans beneath
icy crust
-subject to partial melting due to
tidal forces from Jupiter
-thick atmosphere is ~90%
nitrogen
-instead of oxygen (like Earth)
the atmosphere contains
methane, ethane, argon, and
hydrogen compounds
-surface temperature of 93 K (180oC)
-composed mainly of methane
and ammonia ice
-possible ethane oceans
Io (moon of Jupiter)
- average is about 130 K (-143 oC
-active volcanism
-sulfur dioxide atmosphere
-boiling sulfur and sulfur
dioxide geysers with temps as
high as 2000 K (1723 oC)
Triton (moon of Neptune)
-surface composed of a mixture
of ices of nitrogen, methane,
carbon dioxide, and carbon
monoxide surrounded by a thin
atmosphere
-surface temperature of 40 K (235oC)
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Montana State University
NASA CERES Project – http://btc.montana.edu/ceres
Preliminary Edition