Surface of the Moon

Overview of the Moon's Surface

• The Moon features distinct dark and light spots:

  • Dark Spots (Mare):

    • Known as "maria" (Latin for "seas"), a term from when these were thought to be actual oceans.

    • Composed of basalt formed by ancient lava flows, similar to Earth's oceanic crust.

  • Light Spots (Highlands):

    • Represent elevated regions of lower density, akin to continental crust.

    • These areas float above the denser mare regions.

The Far Side of the Moon

• The far side of the Moon has only been captured in images from space.

• Unique characteristics of the far side include:

  • Predominantly covered in craters with minimal maria or highlands.

  • Presents a stark contrast to the near side, showcasing a different geology.

Craters on the Moon

• The formation of craters is a result of meteoroid impacts:

  • Similar to craters found on Earth, these are round holes created by meteoroids striking the surface.

  • The impact causes:

    • An ejecta blanket (material expelled during impacts).

    • Heat generated from the impact that pulverizes local material, enlarging the crater beyond the size of the impacting meteoroid.

• Crater size facts:

  • On average, craters can be 10 times larger in diameter and 2 times deeper than the meteoroid itself due to the effect of the impact.

Age of Craters

• The majority of lunar craters are estimated to be around 4 billion years old, dating back to the Moon's formative years.

• Newer craters do exist, created by smaller meteoritic impacts that continue to occur.

Micrometeorites

• Micrometeorites are small meteoroids that impact the Moon's surface:

  • Contribute to the continuous smoothing of the lunar surface features.

• The process creates a layer of fine dust known as regolith.

Regolith

• Defined as the layer of dust and debris from meteoritic impacts on the Moon.

• Provides an image of the Moon's surface, including tracks from rovers traversing the regolith layer.