2.5 Lunar Soil and Dust
41
Fig. 2.14 The relationship between the ultimate bearing capacity of lunar soil and the ground
contact pressure
The variation of the conductivity of lunar soil with respect to temperature shows
amorphous characteristics, which means the lunar soil on lunar surface suffers intense
radiation damage. For example, the variation of DC conductivity σ with respect
to temperature of the “Apollo-15” lunar soil (15301, 38) satisfies the exponential
relationship shown below:
σ = 6 × 10
−18 e
0.0237T
(2.9)
where T is temperature (K).
The characteristic of low frequency conductivity of lunar rock is similar to that
of anhydrous silicate minerals on Earth. The variation of DC conductivity σ with
respect to temperature of the “Apollo-16” lunar soil (65015, 6) is similar to that of
lunar soil:
σ = 3 × 10
−4 e
0.0230T
(2.10)
However, the variation of dc conductivity with respect to temperature of the other
lunar rock sample satisfies the expression below:
σ = σ 0 e
E 0 / kT + σ 1 e
E 1 / kT
(2.11)
where k is the Boltzmann constant, E 0 and E 1 is the activation energy, as shown in
Table 2.9.
The conductivity of lunar substance is not only up to temperature, but is also
affected by solar radiation. The solar radiation may greatly change the conductivity of
lunar substance, and therefore causes great charge movement nearby the terminator.
Measurement shows that the dc conductivity of lunar substance varies from 10
−14 S/m
of lunar soil to 10
−9 S/m of lunar rock at night; while exposed to sunlight, the lunar
41
Fig. 2.14 The relationship between the ultimate bearing capacity of lunar soil and the ground
contact pressure
The variation of the conductivity of lunar soil with respect to temperature shows
amorphous characteristics, which means the lunar soil on lunar surface suffers intense
radiation damage. For example, the variation of DC conductivity σ with respect
to temperature of the “Apollo-15” lunar soil (15301, 38) satisfies the exponential
relationship shown below:
σ = 6 × 10
−18 e
0.0237T
(2.9)
where T is temperature (K).
The characteristic of low frequency conductivity of lunar rock is similar to that
of anhydrous silicate minerals on Earth. The variation of DC conductivity σ with
respect to temperature of the “Apollo-16” lunar soil (65015, 6) is similar to that of
lunar soil:
σ = 3 × 10
−4 e
0.0230T
(2.10)
However, the variation of dc conductivity with respect to temperature of the other
lunar rock sample satisfies the expression below:
σ = σ 0 e
E 0 / kT + σ 1 e
E 1 / kT
(2.11)
where k is the Boltzmann constant, E 0 and E 1 is the activation energy, as shown in
Table 2.9.
The conductivity of lunar substance is not only up to temperature, but is also
affected by solar radiation. The solar radiation may greatly change the conductivity of
lunar substance, and therefore causes great charge movement nearby the terminator.
Measurement shows that the dc conductivity of lunar substance varies from 10
−14 S/m
of lunar soil to 10
−9 S/m of lunar rock at night; while exposed to sunlight, the lunar