ASTR 1210 (O'Connell)

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TOPIC GUIDE/OUTLINE FOR THE
TERRESTRIAL PLANETS

Mars Relief Map from the Mars Global Surveyor Mission.
Click for enlargement.

The next 5-6 lectures will cover the terrestrial planets. These include Mercury, Venus, Earth, and Mars and also (from a structural point of view) the Earth's Moon. This page lists the main topics to be discussed.

By comparing the planets and identifying differences and similarities ("comparative planetology") we gain much more information on how they came to be than if we just studied one planet. For instance, the horrific conditions on Venus triggered the realization that a human-induced "Greenhouse effect" could be a threat to the climate on Earth.

A. General Properties

• Near Sun (< 2 AU)

• Dense, rocky materials

• Well defined surfaces (unlike the Jovian planets)

• Atmospheres: None (Mercury, Moon) or thin (Earth, Mars, Venus) by the standards of the Jovian planets (although Venus' atmosphere is 90 times more massive than Earth's)

• Few satellites: Earth (1), Mars (2)

B. Exploration: mainly by space missions since 1960

• Mapping by spacecraft: all. Venus by radar.

• Robot landers: all but Mercury

• Human landings: Moon

• For a history of solar system exploration, both of the terrestrial planets and other bodies, see:
  • Calvin Hamilton's Exploration Page at "Views of the Solar System"

  • This includes a chronology of space missions.

• It's worth noting that any space mission is a major undertaking and typically involves the skills of thousands of people. We have invested a great deal in our exploration of the solar system, but it has paid off in a much better understanding of our own environment.

C. Key Topics

• Earth's uniqueness & biosphere

• Earth interior & plate tectonics

• Moon: impact terrain

• Moon: surface history (from Apollo program) as clue to planet formation/evolution

• Venus: catastrophic resurfacing

• Venus: Greenhouse Effect

• Mars: topography & surface history

• Mars: evidence for water

• Mars: Meteorite evidence for life(?)

• Mars: the canal illusion and "the abode of life"; popular impact via The War of the Worlds; UFO's

• Earth/Venus/Mars: evolution of atmospheres; terrestrial climate change
  Main Lesson: "little differences mean a lot"

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Reading & Web Links:

See individual Study Guides. Reading will cover Chapters 9 and 10 of the Bennett textbook
as well as The War of the Worlds.

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Last modified December 2020 by rwo

Text copyright © 1998-2020 Robert W. O'Connell. All rights reserved. These notes are intended for the private, noncommercial use of students enrolled in Astronomy 1210 at the University of Virginia.