XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3 331
confirmed by NASA7 using data from the Moon Mineralogy
Mapper (M3) onboard Chandrayaan-1. Figure 1 shows the
distribution of water ice at the lunar south pole.
NASA’s Lunar Crater Observation and Sensing Satellite
(LCROSS) was launched in June of 2009.8 The LCROSS
mission objective was to explore permanently shadowed
regions for the presence of water ice. The lunar surface was
impacted by the mission’s Centaur rocket booster and the
subsequent plume of ejected material sampled for volatiles.
Data gathered indicated the presence of almost pure water,
as well as other volatiles such as methane, ammonia, hydro-
gen, carbon dioxide, and carbon monoxide.
The axis of rotation of the Moon has a tilt of 6.68°
compared with Earth’s tilt of 23.44°. Unlike the Earth, the
Moon is nearly perpendicular to the light from the Sun,
as shown in Figure 2. Therefore, at the bottom of very
deep craters located near the lunar poles there are regions
that have never seen Sun light that are called Permanently
Shadowed Regions (PSRs). For example, the Shackelton
crater which is located close to the Moon’s south pole is
4 km deep. Because the PSRs are never exposed to light
from the Sun they are known as “cold traps.” The Lunar
Reconnaissance Orbiter (LRO) has been used to measure
temperatures at the bottom of shadowed craters with results
ranging from 25 to 70 Kelvin (–248 C to –203 C). Due to
this constant cold temperature and water ice that is depos-
ited in a PSR will survive for geological periods of time.
In 2024 NASA plans to send a Volatiles Investigating
Polar Exploration Rover (VIPER),9 Figure 3, to the south
pole region of the Moon. This mission is the first attempt at
extraterrestrial resource mapping. It is expected that depos-
its of icy regolith with substantial water content will be
identified. Regolith is lunar soil which contains no organic
material. Scientific instrumentation carried by VIPER
includes a neutron spectrometer system, a near-infrared
volatiles spectrometer system, a mass spectrometer, and a
regolith and ice drill. Sampling and measurement as deep
as one meter are planned. This mission is planned for 100
days of operations during which VIPER will enter PSRs
where temperatures can be as low as 40 degrees Kelvin.
PROPERTIES OF ICY-REGOLITH:
The Moon’s surface is continuously bombarded by meteor-
ites and many of these contain water ice.10 Ice which sur-
vived impact is scattered over the lunar surface and most
is quickly vaporized and lost to space. However, some will
end up inside the permanently shadowed craters. Once Figure 1. Water ice at lunar south pole7
Figure 2. Moon vs earth axis tilt
confirmed by NASA7 using data from the Moon Mineralogy
Mapper (M3) onboard Chandrayaan-1. Figure 1 shows the
distribution of water ice at the lunar south pole.
NASA’s Lunar Crater Observation and Sensing Satellite
(LCROSS) was launched in June of 2009.8 The LCROSS
mission objective was to explore permanently shadowed
regions for the presence of water ice. The lunar surface was
impacted by the mission’s Centaur rocket booster and the
subsequent plume of ejected material sampled for volatiles.
Data gathered indicated the presence of almost pure water,
as well as other volatiles such as methane, ammonia, hydro-
gen, carbon dioxide, and carbon monoxide.
The axis of rotation of the Moon has a tilt of 6.68°
compared with Earth’s tilt of 23.44°. Unlike the Earth, the
Moon is nearly perpendicular to the light from the Sun,
as shown in Figure 2. Therefore, at the bottom of very
deep craters located near the lunar poles there are regions
that have never seen Sun light that are called Permanently
Shadowed Regions (PSRs). For example, the Shackelton
crater which is located close to the Moon’s south pole is
4 km deep. Because the PSRs are never exposed to light
from the Sun they are known as “cold traps.” The Lunar
Reconnaissance Orbiter (LRO) has been used to measure
temperatures at the bottom of shadowed craters with results
ranging from 25 to 70 Kelvin (–248 C to –203 C). Due to
this constant cold temperature and water ice that is depos-
ited in a PSR will survive for geological periods of time.
In 2024 NASA plans to send a Volatiles Investigating
Polar Exploration Rover (VIPER),9 Figure 3, to the south
pole region of the Moon. This mission is the first attempt at
extraterrestrial resource mapping. It is expected that depos-
its of icy regolith with substantial water content will be
identified. Regolith is lunar soil which contains no organic
material. Scientific instrumentation carried by VIPER
includes a neutron spectrometer system, a near-infrared
volatiles spectrometer system, a mass spectrometer, and a
regolith and ice drill. Sampling and measurement as deep
as one meter are planned. This mission is planned for 100
days of operations during which VIPER will enter PSRs
where temperatures can be as low as 40 degrees Kelvin.
PROPERTIES OF ICY-REGOLITH:
The Moon’s surface is continuously bombarded by meteor-
ites and many of these contain water ice.10 Ice which sur-
vived impact is scattered over the lunar surface and most
is quickly vaporized and lost to space. However, some will
end up inside the permanently shadowed craters. Once Figure 1. Water ice at lunar south pole7
Figure 2. Moon vs earth axis tilt