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December 2003: Issue 1
The Goldilocks Zone
Here's the Scoop!
As scientists have explored the Solar System,
it has appeared that Venus is too hot and Mars is too cold to
support life. It has seemed that Earth is the only place that
is just right for life, and scientists have called these just
right conditions "the Goldilocks Zone." The Goldilocks
Zone is the range of environmental conditions (such as temperature,
pressure, acidity, salinity, etc.) that can support life.
Even here on Earth, there are places that scientists thought
would not fit within the zone – such as deep underground,
or in very hot or cold conditions. However, over the past 30
years, researchers have discovered several organisms that live
in extreme environments on Earth, ranging from very hot deep
sea thermal vents (underwater geysers) to extremely cold seas
under sheets of Arctic ice. The recent discoveries indicate
that this zone is larger than scientists once thought.
Among the researchers studying this are NASA scientists Richard
Hoover and Elena Pikuta, who announced in October the discovery
of an extreme-loving organism they named Tindallia californiensis.
This microorganism makes its home in California’s extremely
salty and alkaline Mono Lake. Earlier this year, Hoover and
Pikuta announced the discovery of another microbe living in
Mono Lake, thriving in the lake’s extreme conditions.
By discovering the extreme conditions in which life on Earth
can exist, scientists can search for comparable conditions in
the rest of the Solar System. Searching for life in the universe
is one of NASA's most important research activities.
Use it in the Classroom!
Planets in a Bottle (113 KB)
Grades K - 4
Each planet has its own unique extreme conditions that would
test the limits of life. Students explore the environmental
conditions on each planet and how they could affect the health
of yeast samples in the lesson Planets in a Bottle. Students mix water, sugar, and
yeast in a plastic bottle and seal it with a balloon. The rate
at which the balloon inflates is proportional to the growth
of the yeast colony. By exposing the bottle to different conditions,
students can simulate the environments of other planets and
decide which seem likely to harbor life. This lesson is also
available online: http://science.nasa.gov/newhome/headlines/msad16mar99_1a.htm.
This lesson is from Science@NASA. For more information, visit
http://science.nasa.gov.
Frozen Seas (18 KB)
Grades 5 - 8
Organisms living in extreme environments must adapt to their
harsh surroundings. In the lesson Frozen
Seas, students research physical and behavioral
adaptations of an Arctic or Antarctic animal. Students gain
an appreciation for the diversity of life and its various adaptations
to extreme temperature conditions. Discuss how these adaptations
could help life to thrive in extreme environments on other worlds
in our Solar System. This lesson is also available online: http://school.discovery.com/lessonplans/programs/BP_frozenseas/.
This lesson is from the Discovery School. For more information
or additional lesson plans, visit www.discoveryschool.com.
What is Necessary for Life? (692 KB)
Grades 9 - 12
In the high school lesson What is
Necessary for Life?, students identify the
resources on Earth that are essential for life to thrive. They
perform experiments with plants and chemosynthetic bacteria,
placing them under various conditions in order to discover the
best way to sustain life. They learn that life will not prosper
in an environment that does not provide the necessary resources.
Discuss the Goldilocks Zone with the students and how their
experiment broadened their understanding of what life needs
to survive.
This lesson is from Earth Systems Science, an Education
Module for Challenger Center’s Journey through the Universe
program. For more information about Journey through the Universe,
visit www.challenger.org/journey
Learn More About It!
To learn more about life in the extreme, visit:
http://science.nasa.gov/headlines/y2003/02oct_goldilocks.htm?list932540
http://science.nasa.gov/newhome/headlines/msad13jan99_1.htm
