Mercury and Venus Lecture Notes

These flashcards cover key vocabulary and concepts related to Mercury and Venus, as discussed in the lecture.

Mercury

The closest planet to the sun, with no moons and a significant temperature range.

Eccentricity

A measure of the deviation of an orbit from circularity, with Mercury having the highest among the planets.

Perihelion

The point in the orbit of a planet where it is closest to the sun.

Aphelion

The point in the orbit of a planet where it is farthest from the sun.

Transit of Mercury

An event that occurs when Mercury passes directly between the Sun and Earth.

Orbital period of Mercury

88 days, the time taken for Mercury to orbit the sun.

Rotational period of Mercury

Just over 58.6 days, the time taken for Mercury to complete one rotation.

Spin-orbital resonance

A condition in which Mercury spins three times for every two orbits around the sun.

Caloris Basin

A large impact feature on Mercury, with terrain found nowhere else in the solar system.

MESSENGER

A NASA mission that provided detailed images and data about Mercury from 2004 to 2015.

Venus

The second planet from the sun, known for its extreme surface temperatures.

Atmospheric pressure on Venus

90 times greater than Earth's at the surface.

Surface temperature of Venus

A uniform 460° C (860° F).

No global magnetic field

Venus lacks a global magnetic field like that found on Earth and Mercury.

Volcanic outgassing

The process that initially created the atmospheres of Earth, Venus, and Mars.

Sulfuric acid rain clouds

The result of Venus's atmosphere primarily composed of CO2.

Venera Missions

A series of Soviet missions that explored Venus, including landers.

Magellanic Orbiter

A U.S. mission that mapped the surface of Venus using radar.

Tectonics on Venus

Not a gradual process as on Earth, characterized by volcanic and tectonic activity.

Greenhouse Effect on Venus

The process that leads to extremely high surface temperatures due to a thick CO2 atmosphere.

Evidence of a Lost Ocean

The higher ratio of deuterium to regular hydrogen on Venus compared to Earth.

Volcanism on Venus

Characterized by 85,000+ volcanoes, many of which are potentially active.

Lava flows

The primary geological features that cover most of Venus’s surface.

Deuterium

An isotope of hydrogen with double the mass of normal hydrogen.

Surface wind on Venus

Little erosion occurs due to low surface winds and a lack of water.

Transit of Venus

An event when Venus passes directly between the Earth and the Sun, next occurring in December 2117.

Earth’s Moon

Natural satellite of Earth, often compared to the inner planets.

Temperature range of Mercury

The largest temperature range of any planet, with extreme highs and lows.

Proximity to the Sun

The close distance of Mercury to the sun, affecting its temperature and atmospheric conditions.

Soviet Russia's Venera Missions

A significant exploration effort that contributed to our understanding of Venus.

Impact craters on Venus

Few impact craters exist due to volcanic activity covering the surface.

Magnetic field

A protective field around a planet, lacking in Venus, unlike Earth and Mercury.

Hydrostatic equilibrium

The state of balance where the internal pressure of a planet adjusts to external pressures.