Liftoff to Learning: The Atmosphere Below
Video Title: The Atmosphere Below
Video Length: 16:02
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Description: Changes in Earth's atmosphere are investigated
from outer space onboard the Space Shuttle.
Grade Level: 5-8
Subjects: Earth Science
Number and Number Relationships
Earth and Space Science
-Structure of the Earth system
-Properties of objects and materials
Unifying Concepts and Processes
-Change, constancy, and measurement
Table of Contents
There are problems occurring in the Earth's atmosphere. Ozone holes, global
warming, air pollution emissions, and predicted increases in skin cancers
have caught the attention of scientists, environmentalists, and political
leaders around the world. Many believe that important changes are taking
place that could have a profound impact on all life. But much about the
atmosphere is still unknown. It is a dynamic system of complex chemical
and physical interactions. Because of its dynamic nature, the atmosphere
is difficult to understand and model.
The atmosphere receives radiation from the Sun and is bombarded by a continuing
stream of particles from the Sun and from deep space. Surrounding Earth
is a magnetic field that captures electrically charged particles and brings
them in contact with the atmosphere's upper reaches. The gases in the
atmosphere absorb radiation and deflect wavelengths that could be harmful
to life. Temperatures and chemical reactions vary widely through the atmosphere's
different layers. Near the Earth's surface, interactions take place with
the land, the oceans, and with human-made pollutants. Furthermore, the
atmosphere changes from day to night, season to season, and from the equator
to the poles.
Atmospheric measurements taken at the Earth's surface and from balloons
and sounding rockets tell only part of the story. Scientists also need
data gathered from the high vantage point of Earth orbit. In March of
1992, NASA embarked on an important new series of atmospheric studies
made from space that take advantage of the unique capabilities of the
Space Shuttle. These studies may help us answer some perplexing questions
about the atmosphere's future as well as our own.
The Space Shuttle Atlantis carried the first of the Spacelab missions
devoted to the study of the atmosphere. Onboard was the Atmospheric Laboratory
for Applications and Science (ATLAS 1), a collection of 13 instruments
designed to conduct 14 investigations in atmospheric science, solar science,
space plasma physics and astronomy for scientists from the United States,
Belgium, France, Germany, Japan, Switzerland and the Netherlands. From
a 300-kilometer-high orbit, inclined 57 degrees with respect to the Earth's
equator, the ATLAS 1 payload was in an advantageous position to observe
the atmosphere, the Sun, and astronomical targets.
The crew of seven maneuvered the spacecraft and continuously controlled
and monitored the experiments in consultation with investigators and planners
on the ground.
Instruments and Purposes
During the 8-day mission, the instruments measured the total energy contained
in sunlight and how that energy varies, measured the chemical composition
of the Earth's upper atmosphere, investigated how the Earth's electric
and magnetic fields and the atmosphere influence one another, and examined
sources of ultraviolet light in the universe. Nine major instruments are
listed below. They are grouped by main purpose. In the next section, these
instruments are discussed in more detail.
Gases and aerosols:
Atmospheric Trace Spectroscopy instrument (ATMOS)
Solar Backscatter Ultraviolet instrument (SSBUV-A)
Solar radiation and atmospheric effects:
Solar Ultraviolet Irradiance Monitor (SUSIM)
Active Cavity Radiometer (ACR)
Measurement of Solar Constant instrument (SOLCON)
Millimeter Wave Atmospheric Sounder (MAS)
Space Experiments with Particle Accelerators (SEPAC)
Far Ultraviolet Space Telescope (FAUST)
The Atmospheric Trace Spectroscopy instrument surveyed atmospheric trace
molecules by measuring the effects they have on infrared radiation. Similar
measurements were also taken by the GRILLE Spectrometer. The data from these
two instruments revealed aerosol bands in the atmosphere that were probably
remnants of the Mt. Pinatubo volcanic eruption in the Philippines.
The Shuttle Solar Backscatter Ultraviolet (SSBUV-A) instrument has flown
previously on three shuttle missions. The SSBUV-A is similar to instruments
on Nimbus and TIROS (televisor infrared satellite) satellites that measure
ozone concentrations at various levels in the atmosphere. In time, data
readings from these satellites fluctuate, making the accuracy of the readings
suspect. Measurements taken by the SSBUV-A are being compared to those from
the satellites to reestablish satellite instrument accuracy and to validate
previously transmitted data.
In a similar vein, the Solar Ultraviolet Irradiance Monitor (SUSIM) and
the Active Cavity Radiometer (ACR) provided data that will insure the continued
accuracy of similar instruments on the Upper Atmosphere Research Satellite
(WARS) which was launched in 1991 by the Space Shuttle Discovery. SUSIM
made very accurate measurements of the Sun's ultraviolet radiation flow
to learn how this radiation changes over time and relate those changes to
changes in the atmosphere. The ACR instrument also measured ultraviolet
radiation and, along with the Measurement of Solar Constant (SOLCON) instrument,
provided a very accurate measure on the solar constant, the amount of energy
the Sun constantly delivers to the atmosphere. Scientists theorize that
changes in the constant of only 0.5 percent per century could lead to global
climatic changes ranging from tropical to ice age conditions. The Millimeter
Wave Atmospheric Sounder (MAS) instrument on ATLAS was also used for comparison
with similar instruments on WARS. MAS recorded important measurements on
ozone and chlorine monoxide, a key trace molecule involved in the destruction
With two exceptions, all thirteen ATLAS 1 instruments had no major problems.
In spite of blown fuses on two of the instruments (Far Ultraviolet Space
Telescope or FAUST and Space Experiments with Particle Accelerators or SEPAC),
all 14 investigations supported by the instruments received significant
data. The FAUST instrument provided astronomers with their first opportunity
to explore wide areas of the sky in the far ultraviolet radiation wavelength
range. Most ultraviolet light coming to Earth from space is filtered out
by the Earth's atmosphere, making it essential to travel into space to study
this radiation firsthand. Previous space-flown ultraviolet instruments have
focused on narrow regions of the sky. Before its power failure, FAUST observed
the nearby Large Magellanic Cloud galaxy to gain information that may help
astronomers better understand the evolution of our own galaxy. A gas trail
behind the cloud was observed that could indicate a region of star formation.
FAUST also made observations of galaxy clusters in the Virgo, Telescopium,
Dorado, and Ophicus constellations.
The SEPAC instrument was used for controlled experiments that were successful
in generating the first artificial auroras ever produced in the Earth's
upper atmosphere. By firing a 7.4 kilowatt electron beam into the Earth's
upper atmosphere, electrons circling atmospheric nitrogen and oxygen atoms
and molecules were excited to higher energy levels. As they resumed to lower
levels, they released light, forming high intensity auroras several kilometers
in diameter. Forty of the 60 beams produced artificial auroras and were
imaged by the Atmospheric Emission Photometric Imaging experiment mounted
in Atlantis's payload bay. The energy output of these auroras was greater
than the energy input from the beam, indicating that the beam may have triggered
larger reactions in the atmosphere. SEPAC was also used to investigate the
interaction of ionized and neutral gases in space by injecting over 1,000
xenon gas clouds into the atmosphere. Furthermore, SEPAC generated radio
waves with about 100,000 electron beam pulses. The pulses were observed
by ATLAS 1 instruments and by over 100 receivers on the ground in the United
States and Japan.
Atmospheric Laboratory for Applications in Science (ATLAS)
- Series of Spacelab-based missions to study the nature of Earth's
atmosphere, environmental problems, and the atmosphere's relationship
to the outer space environment.
Carbon Dioxide - Molecule consisting of one atom of carbon and
two of oxygen.
Chlorofluorocarbons - A series of human-made chemical compounds
used in cooling and other application.
Global Warming - A suspected increase in world-wide temperatures.
Greenhouse Effect - Trapping of solar energy by gases in the
Methane - Molecule consisting of one atom of carbon and four
Oxides of Nitrogen - A group of molecules consisting of nitrogen
Ozone - Molecule of oxygen consisting of three atoms of oxygen.
Ozone Depletion - The destruction of upper atmosphere ozone
molecules through the action of human-made chemicals and sunlight.
Ultraviolet Radiation - Short wave electromagnetic radiation
just beyond the visible violet light.
Upper Atmosphere Research Satellite (UARS) - Scientific satellite
launched by the STS-48 mission in 1991.
These activities will help your students understand the material in "The
Atmosphere Below." In both activities students investigate properties
of the atmosphere.
Two small latex balloons
Two 15-cm pieces of string
Piece of notebook paper
Earth's air has many characteristics. Scientists have developed different
ways of investigating these characteristics. In this exercise students will
investigate an important question about air: Does it have weight?
Attach a balloon to each end of a ruler, being careful to use exactly the
same lengths of string or tape to attach each balloon. Suspend the ruler
on a string at approximately the 15-cm mark to create a balance. With tape,
attach the top of the string to a wall about eye level. Tape the notebook
paper to the wall behind the ruler. Put a pencil mark on the paper above
and below each end of the ruler to mark its beginning position. Remove one
of the balloons and blow into it, inflating it as much as possible. Tie
and reattach the balloon with the same piece of string. Gently pull the
string suspending the ruler away from the wall, allowing the ruler to readjust.
Carefully release the string and check the ruler's new position. Mark the
paper with the pencil again.
|Does the ruler still balance?
Does one balloon now weigh more than the other?
What does this tell you about air?
Was your hypothesis correct? When a number of different experiments
give the same results, the hypothesis may be accepted as a theory.
|Determine the weight of the air in the balloon. (To
do this, the students just have to weigh the balloon deflated, then
inflated and subtract the first number from the second.)
Determine the weight density of the air in the balloon. (Find the
volume of air by using a similar balloon. Put water into it until
it has about the same size as the balloon with air. Then measure the
volume of water; this will be about the same as the volume of air.
Divide this number into the air's weight from Extension 1. This is
the weight density of the air.)
Nothing but the Truth
Pencils or pens
All the mysteries that ATLAS 1 scientists investigated involve possible
causes of atmospheric changes. To obtain the most accurate information,
researchers must measure chemicals at different altitudes in the atmosphere
in sunlight and in darkness, and during all seasons for many years. Even
then, scientists have more questions: Are the instruments measuring accurately?
What were conditions nearer the ground when measurements were made from
space? How are conditions in the middle atmosphere related to events in
the troposphere? To help answer these questions, researchers use airplanes,
balloons, rockets, and ground measurements to double check and add to
data obtained from space. These efforts are called ground-truth studies
and make remotely sensed data even more accurate and important. You, too,
can perform ground-truth studies.
Check the newspaper daily and record information on temperature highs
and lows, amount of precipitation and humidity. Keep these charts and,
as the year progresses, figure weekly and monthly averages for your area.
You may want to compare these with figures from previous years using an
almanac or examining old newspapers in the microfiche section of your
library. You might also want to make your own measurements of rainfall,
snowfall and high and low temperatures. Different groups may want to select
forecasters on several radio or TV stations to determine which predicted
results are closest to those actually measured.
|What do you notice about temperature highs
and lows, precipitation, and humidity throughout the year?
Do these seasonal variations mean that the climate is changing?
If you investigate measurements from past years, do changes necessarily
mean that the climate is changing?
How accurate are the weather forecasts in your area?
Calculate weekly, monthly, and yearly averages of temperature and rainfall
in your area. Make a bar chart showing average temperatures for each time
span. Another important statistic is how much temperature and rainfall changes
differ from the average. This difference is called the "standard deviation"
because it measures how much something "deviates" or differs from
NASA Publications ATLAS Educator Slide Set, National Aeronautics and Space
Administration, Education Division, 1991.
The Greenhouse Effect, United States Department of Energy, 1991.
Rosenthal, D., Golden, R., Global Warming High School Science Activities,
Climate Protection Institute, 1991.
Snow, R., Golden, R., Global Warming Social Studies Activities, Climate
Protection Institute, 1991.
USA Today. Earth Today - Your Place in the Environment, Teacher's
Guide, Gannett Co. 1990. Sunlight. Earthwise Environmental Learning Series,
V1n2, WP Press, 1992.
STS-45 Crew Biographies
Brian Duffy (U. Col.,
Kathryn D. Sullivan (Ph.D.)
David C. Leestma (Capt., USN).
Byron K. Lichtenberg (Sc.D.).
Dirk D. Frimout (Ph.D.).
To obtain biographic information, click on highlighted names