Andrew Yee[_1_]
June 7th 07, 01:02 AM
News Service
University of Michigan
412 Maynard
Ann Arbor, MI 48109
Contact: Nancy Ross-Flanigan
Phone: (734) 647-1853
May 23, 2007
Shine on, shine on, climate monitoring station: Moon-based observatories
proposed
ANN ARBOR, Mich. -- Poets may see "a face of plaintive sweetness" or "a
cheek like beryl stone" when they look at the moon, but Shaopeng Huang sees
something else altogether: the ideal location for a network of observatories
dedicated to studying climate change on Earth.
Using data from an Apollo 15 experiment whose original intent was thwarted
by unanticipated lunar surface conditions, the University of Michigan
geophysicist recently showed that surface temperatures on the near side of
the moon accurately record important information about Earth's climate
system.
Based on his analysis, recently published online in Advances in Space
Research, Huang is calling for an international effort to develop and deploy
monitoring stations on the moon for the study of terrestrial climate change.
Global climate change is driven by an imbalance between incoming energy from
the sun and outgoing energy from Earth. Without understanding the climate
system's inputs and outputs -- its so-called energy budget -- it is
impossible to tease out the relative contributions of natural and
human-induced influences and to predict future climate, Huang said.
But detecting changes in the energy budget is difficult with existing
ground-based and space-borne technologies, he noted. Fortunately,
instruments left behind by the Apollo 15 astronauts -- all U-M alumni,
incidentally -- inadvertently provided just the necessary measurements.
"One of the main scientific objectives of the Apollo 15 mission was to drill
two boreholes about three meters into the lunar soil and insert specially
designed probes," Huang said. "The point was to see how temperature varies
with depth, in order to calculate the heat flow outward from the interior of
the moon." But drilling in the moon's powdery soil, or regolith, turned out
to be much more difficult than expected.
"The Apollo 15 crew overspent their precious time on the moon for this
particular task, yet could only penetrate a little more than half the depth
they wanted to reach. When the probes were inserted into the boreholes,
several thermometers designed for measuring subsurface temperature ended up
measuring surface temperature instead."
Consequently, NASA acquired 41 months-worth of records of the moon's surface
temperature.
Originally, Huang was interested in the moon borehole data because he and
U-M colleague Henry Pollack have been using data from holes bored into Earth
to reconstruct Earth's surface temperature history. He thought they might be
able to apply techniques developed for that project to reconstruct the
moon's surface temperature history. But when he examined the moon data set,
he realized it could provide valuable information on Earth's climate shifts.
On the near side of the airless moon, where Apollo 15 landed, surface
temperature is controlled by solar radiation during daytime and energy
radiated from Earth at night. Huang showed that due to an amplifying effect,
even weak radiation from Earth produces measurable temperature changes in
the regolith. Further, his revisit of the data revealed distinctly different
characteristics in daytime and nighttime lunar surface temperature
variations.
This allowed him to uncover a lunar night-time warming trend from mid-1972
to late 1975, which was consistent with a global dimming of Earth that
occurred over the same period and was due to a general decrease of sunlight
over land surfaces. (Widespread ground-based radiation records from that
period show that solar radiation reaching Earth's surface during that period
decreased significantly, for reasons that are not completely understood.)
Huang's study demonstrated that signals from the energy budget of Earth's
climate system are detectable on the moon and can be useful in monitoring
and predicting climate change.
For that and other reasons, the moon is the perfect place for a system of
observatories, Huang said. "As the sole natural satellite of Earth, the moon
is an enduring platform without complications from atmosphere, hydrosphere
or biosphere, and could provide records of Earth's radiation budget that
would complement ground-based and man-made satellite records."
Huang would like to see his findings put to good use -- and soon.
"Global warming on Earth is among the most profound scientific, social,
economical and political challenges of our time," he said. "At the same
time, countries around the world are racing to launch missions to the moon.
The time could not be better to join forces to create a network of
temperature and radiation observatories on the moon for the purpose of
studying climate change on Earth."
Huang received funding for the study from the National Science Foundation
and the Michigan Space Grant Consortium.
Related Links:
* Shaopeng Huang
http://www.geo.lsa.umich.edu/~shaopeng/
* Advances in Space Research
http://www.elsevier.com/wps/find/journaldescription.cws_home/644/description#description
University of Michigan
412 Maynard
Ann Arbor, MI 48109
Contact: Nancy Ross-Flanigan
Phone: (734) 647-1853
May 23, 2007
Shine on, shine on, climate monitoring station: Moon-based observatories
proposed
ANN ARBOR, Mich. -- Poets may see "a face of plaintive sweetness" or "a
cheek like beryl stone" when they look at the moon, but Shaopeng Huang sees
something else altogether: the ideal location for a network of observatories
dedicated to studying climate change on Earth.
Using data from an Apollo 15 experiment whose original intent was thwarted
by unanticipated lunar surface conditions, the University of Michigan
geophysicist recently showed that surface temperatures on the near side of
the moon accurately record important information about Earth's climate
system.
Based on his analysis, recently published online in Advances in Space
Research, Huang is calling for an international effort to develop and deploy
monitoring stations on the moon for the study of terrestrial climate change.
Global climate change is driven by an imbalance between incoming energy from
the sun and outgoing energy from Earth. Without understanding the climate
system's inputs and outputs -- its so-called energy budget -- it is
impossible to tease out the relative contributions of natural and
human-induced influences and to predict future climate, Huang said.
But detecting changes in the energy budget is difficult with existing
ground-based and space-borne technologies, he noted. Fortunately,
instruments left behind by the Apollo 15 astronauts -- all U-M alumni,
incidentally -- inadvertently provided just the necessary measurements.
"One of the main scientific objectives of the Apollo 15 mission was to drill
two boreholes about three meters into the lunar soil and insert specially
designed probes," Huang said. "The point was to see how temperature varies
with depth, in order to calculate the heat flow outward from the interior of
the moon." But drilling in the moon's powdery soil, or regolith, turned out
to be much more difficult than expected.
"The Apollo 15 crew overspent their precious time on the moon for this
particular task, yet could only penetrate a little more than half the depth
they wanted to reach. When the probes were inserted into the boreholes,
several thermometers designed for measuring subsurface temperature ended up
measuring surface temperature instead."
Consequently, NASA acquired 41 months-worth of records of the moon's surface
temperature.
Originally, Huang was interested in the moon borehole data because he and
U-M colleague Henry Pollack have been using data from holes bored into Earth
to reconstruct Earth's surface temperature history. He thought they might be
able to apply techniques developed for that project to reconstruct the
moon's surface temperature history. But when he examined the moon data set,
he realized it could provide valuable information on Earth's climate shifts.
On the near side of the airless moon, where Apollo 15 landed, surface
temperature is controlled by solar radiation during daytime and energy
radiated from Earth at night. Huang showed that due to an amplifying effect,
even weak radiation from Earth produces measurable temperature changes in
the regolith. Further, his revisit of the data revealed distinctly different
characteristics in daytime and nighttime lunar surface temperature
variations.
This allowed him to uncover a lunar night-time warming trend from mid-1972
to late 1975, which was consistent with a global dimming of Earth that
occurred over the same period and was due to a general decrease of sunlight
over land surfaces. (Widespread ground-based radiation records from that
period show that solar radiation reaching Earth's surface during that period
decreased significantly, for reasons that are not completely understood.)
Huang's study demonstrated that signals from the energy budget of Earth's
climate system are detectable on the moon and can be useful in monitoring
and predicting climate change.
For that and other reasons, the moon is the perfect place for a system of
observatories, Huang said. "As the sole natural satellite of Earth, the moon
is an enduring platform without complications from atmosphere, hydrosphere
or biosphere, and could provide records of Earth's radiation budget that
would complement ground-based and man-made satellite records."
Huang would like to see his findings put to good use -- and soon.
"Global warming on Earth is among the most profound scientific, social,
economical and political challenges of our time," he said. "At the same
time, countries around the world are racing to launch missions to the moon.
The time could not be better to join forces to create a network of
temperature and radiation observatories on the moon for the purpose of
studying climate change on Earth."
Huang received funding for the study from the National Science Foundation
and the Michigan Space Grant Consortium.
Related Links:
* Shaopeng Huang
http://www.geo.lsa.umich.edu/~shaopeng/
* Advances in Space Research
http://www.elsevier.com/wps/find/journaldescription.cws_home/644/description#description