Astro 105

Apollo 14 (February 1971)

Mission Overview

• Crew: Alan Shepard (Commander), Stuart Roosa (Command Module Pilot), Edgar Mitchell (Lunar Module Pilot)

• Landing Site: Fra Mauro formation, chosen as an alternative after Apollo 13 failed to land.

• Objective: Study the Fra Mauro highlands to gather samples ejected by the Imbrium impact, one of the Moon’s most significant ancient impacts.

Key Activities

• Cone Crater Traverse:
  
  

  • The astronauts aimed to collect deep-seated lunar materials by climbing the steep slope of Cone Crater.

  • Due to navigation difficulties, they stopped just 15 meters from the rim, unknowingly missing the ideal sampling location.

  • Nevertheless, they retrieved rocks likely ejected from deeper lunar layers.

• “Big Bertha” (Sample 14321):
  
  

  • A 9 kg breccia found at the landing site.

  • Later studies suggested it may contain a piece of Earth’s crust, potentially making it the first known terrestrial rock found on the Moon.

• Lunar Equipment Used:
  
  

  • Modular Equipment Transporter (MET): A hand-pulled cart to carry tools and samples.

  • ALSEP (Apollo Lunar Surface Experiments Package): Left behind to measure moonquakes, solar wind, and heat flow.

Scientific Impact

• Dating the Imbrium Basin:
  
  

  • Samples from Fra Mauro were found to be 3.85 to 3.9 billion years old, confirming the impact age.

  • This was a key step in establishing a lunar impact chronology.

• Moon’s Surface Evolution:
  
  

  • Showed that highland regions were heavily reworked by impacts rather than volcanism.

  • Provided key insight into how early planetary crusts evolved.

Apollo 15 (July 1971)

Mission Overview

• Crew: David Scott (Commander), Alfred Worden (Command Module Pilot), James Irwin (Lunar Module Pilot)

• Landing Site: Hadley-Apennine region, near Hadley Rille and the Apennine mountains, at the edge of the Imbrium Basin.

• Firsts in Apollo 15:

  • First extended lunar stay (67 hours on the surface).

  • First mission with the Lunar Rover, enabling greater mobility (traveled over 27 km).

  • First deep-space EVA: Worden conducted an EVA outside the Command Module to retrieve film from scientific cameras.

Key Activities

• Hadley Rille Exploration:
  
  

  • A deep channel believed to be a collapsed lava tube.

  • Provided insight into lunar volcanic processes and how lava once flowed on the Moon.

• Spur Crater and the “Genesis Rock” (Sample 15415):
  
  

  • A 4.5 billion-year-old anorthosite, believed to be a piece of the Moon’s original crust.

  • Confirmed that the Moon’s early crust was rich in feldspar, supporting the magma ocean hypothesis.

• Green Glass Spherules (Sample 15426):
  
  

  • Volcanic glass indicating fire-fountain eruptions occurred in the Moon’s past.

  • Helped scientists understand the presence of lunar volatiles, possibly including traces of water.

• ALSEP Deployment:
  
  

  • Measured moonquakes and heat flow, providing new data on the Moon’s interior.

Scientific Impact

• Lunar Crust Formation:
  
  

  • The Genesis Rock provided direct evidence of the Moon’s differentiation, meaning it had once been covered in a molten ocean.

• Ancient Lunar Volcanism:
  
  

  • Samples showed that lava flows were more extensive than previously thought.

  • The discovery of Hadley Rille’s structure hinted at underground lava tubes, which could be useful for future lunar bases.

• Increased Exploration Capabilities:
  
  

  • The Lunar Rover significantly improved scientific returns, setting the stage for Apollo 16 and 17.

Apollo 16 (April 1972)

Mission Overview

• Crew: John Young (Commander), Thomas Mattingly (Command Module Pilot), Charles Duke (Lunar Module Pilot)

• Landing Site: Descartes Highlands, chosen to investigate whether the Moon’s highlands were formed by volcanic activity.

• Objective:

  • Test the “Hot Moon” hypothesis (theory that highland regions formed through volcanic processes).

  • Study materials from outside the mare regions to understand early lunar crust evolution.

Key Activities

• Traverse to North Ray Crater:
  
  

  • The largest crater visited by Apollo astronauts.

  • Collected large breccias, some over 11 kg, showing that the highlands were formed by impact, not volcanism.

• House Rock (Sample 67015):
  
  

  • A massive breccia boulder, estimated to be 4.2 billion years old.

  • Provided a look into the Moon’s earliest impact history.

• Lunar Rover Performance:
  
  

  • Allowed them to explore 26.7 km across rough terrain.

  • Equipment overheating became an issue but was managed successfully.

• ALSEP Deployment:
  
  

  • Included a magnetometer, revealing that some lunar rocks had weak magnetic fields.

  • Gave new clues about the Moon’s early magnetic history.

Scientific Impact

• Disproving the “Hot Moon” Hypothesis:
  
  

  • No volcanic rocks were found—highlands were shaped by impacts.

  • This helped confirm that the Moon’s surface evolved primarily through impacts, not internal volcanism.

• Early Lunar History:
  
  

  • The breccias collected at North Ray Crater showed that major impact events occurred over 4 billion years ago.

  • Reinforced the idea of the Late Heavy Bombardment, a period of intense asteroid impacts between 4.1 and 3.8 billion years ago.

• Lunar Magnetic Field Evidence:
  
  

  • Some highland rocks had traces of magnetization.

  • Suggested that the early Moon may have had a weak magnetic field at some point.

Final Summary and Exam Tips

Major Themes Across Apollo 14–16:

• Lunar Impact History:
  
  

  • Apollo 14: Helped date the Imbrium Basin impact (~3.85 billion years old).

  • Apollo 16: Showed that the highlands were shaped by even earlier impacts (~4.2 billion years ago).

  • Apollo 15: The Genesis Rock provided evidence of the Moon’s primordial crust.

• Volcanism vs. Impact Processes:
  
  

  • Apollo 14 & 15: Found evidence of ancient lunar volcanism (green glass, Hadley Rille lava tubes).

  • Apollo 16: Disproved the idea that the highlands were volcanic—they were shaped by asteroid impacts.

• Evolution of the Moon’s Surface:
  
  

  • Apollo 14: Fra Mauro samples confirmed the age and scale of Imbrium ejecta.

  • Apollo 15: Showed the magma ocean hypothesis was correct.

Apollo 16: Indicated the Moon’s crust formed over 4 billion years ago.