Topic 2

• What are craters on the Moon caused by?

  Impact features caused by meteorites or comets
• When were most craters on the Moon formed?

  Very early on in the Moon’s evolution
• What is libration in relation to the Moon?

  The “wobble” of the Moon due to its orbital characteristics
• What causes latitude libration of the Moon?

  The plane of the Moon’s orbit being about 5° off the ecliptic
• What causes longitude libration of the Moon?

  The elliptical nature of its orbit
• What are maria on the Moon?


  Darker lowland areas that are quite smooth and featureless
• How were the maria formed?


  By volcanic activity that flooded these areas with lava
• What is the rotation and revolution period of the Moon?

  27.3 days
• What does the synodic month refer to?

  The time from full moon to full moon, which is 29.5 days
• What are terrae on the Moon?

  Brighter highland areas
• What are Maria on the Moon?

  Dark areas on the Moon
• What is the Latin term for sea?

  Mare
• What is the plural of Mare?

  Maria
• What percentage of the lunar surface is classed as maria?

  17%
• Why were maria mistaken for seas by early astronomers?

  Because they are dark areas on the Moon
• What is the collective name for highlands on the Moon?

  Terrae
• How do terrae differ from maria?

  Terrae are brighter and higher than maria
• Why do maria appear darker than terrae?

  Because they contain more iron-rich elements
• Where are there fewer maria on the Moon?

  On the far side of the Moon
• How old are the rocks brought back from the Apollo missions?

  1. 4 billion years old
• What was the 'Heavy Bombardment' period on the Moon?


  A time of frequent and violent impacts on the Moon
• What happened to the Moon after the Heavy Bombardment?

  It underwent a time of volcanic activity
• What did the volcanic activity on the Moon produce?

  Lava that turned to basalt
• What did the basalt lava do to the lower impact areas?

  It flooded them and covered other features
• What remains untouched by volcanic activity on the Moon?

  The highlands
• How do the number of craters on terrae compare to those on maria?

  There are many craters on terrae and fewer on maria
• What primarily causes craters on the Moon's surface?

  Meteorites or comets colliding with the Moon
• When did most of the Moon's craters form?

  During the Moon's early evolution
• What do craters typically consist of?

  A raised wall or rim with a central peak
• How can craters be best observed?

  When the Moon is not full, to emphasize shadows
• What is the depth of the deepest crater, Newton?

  29,000 ft
• How does the depth of the Newton crater compare to Mount Everest?

  It is as deep as Mount Everest is high
• What might craters like Newton contain?

  Frozen water deposited from comets
• What is the diameter of the largest crater on the Moon?

  231 kilometres
• How many craters can be seen from Earth?

  Over half a million
• What are the names of some mountain ranges on the Moon?

  Appenines, Alps, Caucasus
• How high can some individual peaks on the Moon rise?

  Nearly 5,000 metres
• What is the Appenine range's location on the Moon?

  Between Mare Imbrium and Mare Serenitatis
• How are lunar mountains thought to have been formed?

  By impacts that released magma under the early lunar surface
• What are valleys on the Moon?

  Long depressions on the Moon's surface