2232G

• Mercury

  • 1st planet from the sun
  • Smallest planet in the solar system
  • Little bigger than the moon
  • Heavily cratered surface
  • Impact cratering the most common geographical process in our solar system
  • Has no atmosphere
  • The gasses escape to space
  • No satellites

  
• Roman Mythology

  • Named after the winged messenger of the gods
  • Also the god of thievery, commerce, and travel
• Mariner 10 (1973-1975)

  1. Made 3 flybys

  2. Goals: study its atmosphere, surface, and physical characteristics

  3. Mapped 40-45% of the surface
• MESSENGER (Mercury Surface, Space Environment Geochemistry and Ranging)

  1. Launched Aug. 3 2004

  2. Goals: Map Surface composition, and study magnetic field and interior structure

  3. Crashed into Mercury on 30 April 2015, ending the mission
• MARINER 10

  • Sunshade prevents the spaceship from heating up and frying circuits
• MESSENGER

  • Advancement from the Mariner
  • More instrumentation and more sophisticated
  • Cosmic rays results in Gamma rays and neutrons sent to outer space and messenger could detect these rays
  • From the sun you get solar x rays resulting in elements to fluores or fluorescent x rays sent to outer space and messenger could detect these rays and measure more elements
• Almost 39% of the distance from the sun that we are
• Average density is almost 5.5 times more dense than water. Double the material on earth
• 2.5 times smaller gravity than on earth
• Axis of rotation is 90 or perpendicular to the plane in which it orbits around the sun
• 2% of the speed at which earth rotates
• Orbits a lot faster around the sun than we do
• Because of its rotation we get this extreme variation of temperatures
• Internal Structure

  • Our Mantle is thicker and larger
  • Core relative to the size of the planet
  • 60% of mercury
• Surface Composition

  • Color enhances chemical, mineralogical, and physical differences between rocks
  • Light blue/white areas: young crater rays
  • Darker blue areas: mercury's crust (low reflectance material)
  • Yellow/tan areas: volcanic plains
  • MESSENGER data provides evidence for graphite (pre carbon) on mercury (<4%)
  • The Planet's surface is enriched in Sulfur and Carbon yet depleted in iron.
  • Surface is also enriched in Magnesium but depleted in Aluminum and Calcium
  • Suggests that Mercury underwent a magma ocean early in its history
• Cratered Terrain and Intercrater plains

  • Heavily cratered regions
  • Broad areas of gently rolling plains, impact craters, and basins
• Caloris Basin


  • Multi-ring basin ~ 1,300 km diameter
  • Drive from london ON - other side of ontario
• Smooth Plains

  • Resemble lunar Maria
  • Sparsely cratered
  • Level, and fill, major depressions

  
• Volcanism

  • Plains volcanism
  • Pyroclastic Volcanism
• No Atmosphere

  • Sharp line to the blackness of space
  • But has an exosphere
  • Formed by atoms escaping to space from solar wind and impact events
• Formation of Mercury

  1. Metal enrichment towards the center with increasing temp and pressure occurred

  2. Increasing density towards the center

  3. Separation of metal and silicate

  4. More reducing conditions towards the center

  5. Started with a proto-mercury planet

  6. Impactor struck it

  7. Molten mercury remnant