Chapter 9: Atmospheres of the Terrestrial Planets

What planet lost its primary atmosphere and retains a tenous secondary atmoshpere?

Mars

Which planet retained neither its primary nor secondary atmospheres?

Mercury

Which objects in our terrestrial solar system held on to their secondary atmospheres? Which ones could not?

More massive planets could retain the gravity of their secondary atmosphere such as Venus, Earth, and Mars. Mercury and the Moon are too small.

How is ozone depletion caused?

Ozone depletion is caused by a seasonal buildup of atmospheric halogens like chlorine, flourine, and bromine.

How is ozone formed and where is it mainly located on Earth?

Ozone is formed when UV light from the Sun breaks molecular oxygen into its indivisual atoms. These oxygen atoms can then recombine with other oxygen molecules to form ozone. Most of Earth's natural ozone is concentrated in the upper atmosphere called the stratosphere.

For what two main reasons do Venus and Mar's atmospheres differ today?

Planetary mass and the greenhouse effect.

What replaces the oxygen lose through oxidation, on Earth?

Plants

True or false: A planet with significant amounts of oxygen in its atmosphere requires a way to replace oxygen lost through oxidation.

TRUE

List the major developments of life as the percentage of Earth's atmosphere rose from most basic to most developed.

(1) First oxygen release pf cyanobacteria (2) First Eukaryotes (3) Multicellular organisms (4) First Vertebraes (5) Arthropods (6) First flowering plants (7) Age of reptiles

How is an atmosphere formed?

1. Gases in a protoplanet disk, mostly hydrogen and helium are captured, forming primary atmospheres 2. Sunlight heats the atmospheres. Rapid thermal motion of light atoms and molecules caused the primary atmospheres to escape. 3. Valcanoes release gases and impacting comets and asteroids contribute water + other molecules to form secondary atmospheres, which some planets held on to.

What is the mass of nitrogen in Mars's atmosphere?

4.18 x 10^14 kg

Which two elements compose the majority of Earth's atmosphere?

4/5 - Nitrogen 1/5 - Oxygen

What is solar wind and what is its impact on a planet's atmosphere?

A constant stream of charged particles from the Sun. The solar wind can accelerate atmospheric particles to escape velocity.

What is a bar?

A unit of pressure used to measure Earth's atmospheric pressure.

How has the atmospheric greenhouse effect made the composition of Earth's atmosphere so different from the atmospheres of Venus and Mars?

Although Venus and Earth are roughly the same mass, Earth is farther away from the Sun which allows Earth to have water.

Who does planetary mass affect a planets atmosphere?

Although both Venus and and Mars are mostly Carbon dioxide, the total amount of atmosphere differs. Mars has a smaller and weakening atmosphere than Venus.

What is the Hadley Circulation?

An air pattern that moves between the equator and poles of a planet.

How can gas molecules escape from a planet?

Any object can escape a planet if the object exceeds the escape velocity.

Why is decomposition of ammonia by sunlight the primary source of molecular nitrogen in the atmospheres of terrestrial planets?

Because sunlight UV light easily breaks down ammonia and methane intro hydrogen and nitrogen, molecules less likely to escape into space.

How did the giant planets distance to the sun enable them to retain nearly all of their primary atmospheres?

Because the giant planets were farther from the Sun, they were much more massive and were cooler which resulted in stronger gravity and lower temperatures.

Do the moon and mercury have an atmosphere today?

Both have virtually no atmosphere possibly due to solar flares and decreases in their magnetic fields which caused them to cool.

The main greenhouse gases in the atmospheres of the terrestrial planet are...

Carbon dioxide and water vapor

What two things does the amount of carbon dioxide in an atmosphere rely on?

Depends on the the source (the places where is originated from) and the sinks (where the carbon dioxide goes).

What causes auroras?

Emission in the upper atmosphere of a planet from atoms that have been excited by collisions with energetic particles from the planet's magnetosphere.

How do molecules move within a planetary atmosphere, in relation to the temperature and size of a molecule?

For a gas at a given temperature, the less massive molecules move faster than the more massive ones. Fast molecules near the ground will collide with other molecules before they can escape. At upper levels of the atmosphere, fast molecules escape.

What are greenhouse gases and what do they do to a planet's atmosphere?

Gases that transmit visbible radiation but absorb infrared radiation are greenhouse gases. Examples include water vapor, carbon dioxide, methane, and industrail chemicals, Greenhouse gases cause the surface temperature to rise.

What two elements make up earth's primary atmosphere?

Helium and Hydrogen

What causes a planet to have a stronger Coriolis effect and stronger solar winds?

How fast the planet rotates.

How many bars is Earth's atmopsheric pressure at sea level?

I bar

Which planet still maintains its primary atmosphere?

Jupiter

What two things cause weather?

Local winds and convection.

What are Zonal winds?

The east-west component of a wind.

What is global circulation?

The overall planetwide circulation pattern of a planet's atmosphere.

What is cyclonic motion?

The rotation of a weather system resulting from the Coriolis effect as air moves toward a region of low atmopsheric pressure.

What is the greenhouse effect?

The solar heating of air in an enclosed space, such as a closed building or car, resulting primarily from the inability of the hot air to escape.

What two qualities distinguish weather and climate?

Time and size

all weather and wind on earth are a result of convection in the

Troposphere

In order from highest to lowest, what are the layers of Earth's atmosphere?

Troposphere Tropopause Stratosphere Mesosphere Thermosphere Ionosphere Magnetosphere

The smaller the atmosphere is, the less likely it is to experience the greenhouse effect -true or false?

True; A more massive atmosphere is more hot which can lock up molecules in its atmosphere much easier.

What planet lost its primary atmosphere but retains a desnse secondary atomosphere?

Venus

Which two planets in the solar system were once believed to have water or may have water?

Venus and Mars

Which of the three planets today have significant secondary atmospheres?

Venus, Earth, and Mars

What is the atmospheric greenhouse effect?

Warmed surface radiates the energy in the infrared region of the spectrum which is then converted to thermal energy. Some of the thermal energy returns to the ground, raising the planet's surface temperature. Now, the the planet's surface recieves thermal energy from both the Sun and the atmosphere.

What causes wind?

When a gas is heated up, its pressure increases which causes it to push into its surroundings - this is wind.

What is an atmosphere?

a blanket of gases that surrounds a planet that warms and sustains a planets climate.

Which as reasons Mercury has so little gas in its atmosphere?

a. Its escape velocity is low b. Its mass is small c. It is close to the Sun d. It has a high temperature

Over the last 800,000 years, Earth's temperature has closely tracked a. solar luminosity b. oxygen levels in the atmosphere c. the size of the ozone hole d. carbon dioxide levels in the atmosphere

d. Carbon dioxide levels in the atmosphere

How high you would have to go in Earth's atmosphere to experience the same atmospheric pressure as you would if you were standing on Mars.

more than 36 km

What is cyanobacteria?

photosynthetic bacteria/blue-green algae that contain chlorphyll which began releasing oxygen into the Earth's atmosphere about 2.8 billion years ago.