Rare Resources

Question 1

What are some important rare resources?

Answer 1

• Solar wind implanted particles
• Rare earth elements
• Platinum group metals

Question 2

What are the most abundant solar wind implanted particles?

Answer 2

H, He, C, N, O

Question 3

What are important notes for SWIP?

Answer 3

• Not abundant resource
• Cant be mined independently
• Larger uncertainty for H
• More on far side than near side

Question 4

What are the uses of Sulfur?

Answer 4

Concrete, Sealant, Fluid

Question 5

What are the lunar sources of carbon?

Answer 5

• Solar wind
• Vulcanization during impact
• Outgassing

Question 6

What are rare earth elements?

Answer 6

A group of 17 metallic elements with similar properties

Question 7

What are PGMs?

Answer 7

Platinum group metals

Six noble metals

Tend to occur together

Question 8

What does SWIP mean?

Answer 8

Solar wind implanted particles

Question 9

What are points about implantation of SWIP?

Answer 9

• Implantation depths < 1 micro m
• Most concentrated in the fines
• Abundance correlates with soil maturity

Question 10

What are points about SWIP dependency on lunar chemistry?

Answer 10

• He and Ne contents are much higher in Ilmenite that other minerals
• He/Ne correlate with TiO_2

Question 11

What are points about Sulfur on the moon?

Answer 11

• Primarily available as sulfide in troilite though larger deposits might exist

Question 12

What are facts about 3He on the moon?

Answer 12

• Can be up to 15 ppb in sunlit areas and 50ppb in permanent shadow zones (4.2 ppb global average)
• High abundance possible in high Ti-basalts at Mare Tranquilitatis and Oceanus Procellarum

Question 13

What are facts about the D-3He fusion cycle?

Answer 13

• Releases far fewer neutrons
• High conversion efficiency
• Lower radioactivity risk
• Requires higher plasma temp,

Question 14

How are SWIPs distributed on the Moon and why?

Answer 14

• More SWIP on the far side than on the near side, because the Moon spends about a fourth of its time in the tail of Earth’s magnetosphere
• Regional variation due to local magnetic anomalies

Question 15

Why is He3 an important rare resource?

Answer 15

Energy source for fusion reactions

Question 16

What is the abundance of primordial He3 on Earth?

Answer 16

• Earth’s mantle (not directly accessible)
• Atmosphere
• Natural gas deposits

Question 17

How can He3 be produced?

Answer 17

Beta decay of tritium

Question 18

What is the total estimated mass of He3 on the moon?

Answer 18

Between 0.66 Mton and 0.84 Mton

Question 19

What is a problem of fusion with tritium and how can it be solved with He3?

Answer 19

• Shortage of Tritium
• Not many sources
• ITER consumes 1kg annually
• He3 is more sustainable, but rare on Earth

Question 20

What are uses of PGMs?

Answer 20

• Highly resistant to wear and tarnish, chemical attack, excellent high-temperature characteristics, high
  mechanical strength, good ductility, and stable electrical properties
• Found in one in four products surrounding us

Question 21

How do extraterrestrial source of REE and PGM compare to Earth?

Answer 21

• Lunar REE are low compared to Earth
• C-type asteroids contain less REE but more PGM compared to Earth

Question 22

What are the different types of asteroids?

Answer 22

• The C-type (chondrite) asteroids are most common. They consist of clay and
  silicate rocks, and are dark in appearance. They are among the most ancient
  objects in the solar system.
• The S-type (“stony”) asteroids are made up of silicate materials and nickel-iron.
• The M-type asteroids are metallic (nickel-iron).