HW 12: Venus and Mars
Determine whether the given terms are properties of Mars' atmosphere, Venus' atmosphere, or both.
MARS: - thin - changes seasonally BOTH: - mostly carbon dioxide VENUS: - very thick - clouds of sulfuric acid - opaque
Evidence clearly suggests that significant amounts of water can be found on Mars today. Determine whether each form of water is or is not a present form of water on Mars.
PRESENT FORMS OF WATER ON MARS: - water frozen in polar ice caps - layer of permafrost underneath the surface NOT PRESENT FORM OF WATER ON MARS: - deep oceans of liquid water - streams and rivers flowing through gulleys and river deltas - precipitation from thick atmosphere rich in water vapor
Which of the statements are true of the surface of Venus, and which of the statements are false?
TRUE: - relatively flat and smooth, with gently rolling plains - numerous shield volcanoes and lava flows FALSE: - many small continental regions - very old surface with many impact craters
Mars appears red because
there is plentiful dust rich in iron covering its surface.
Photographs obtained by the NASA probe Mariner 9 revealed a vast canyon on Mars that has since been named Valles Marineris. Select the true statements concerning the Valles Marineris.
- It is longer than the distance between Boston and Washington, D.C. - Its widest point is wider than the Grand Canyon's width. - It is a rift valley.
Identify the pieces of evidence that indicate that liquid water once existed on Mars.
- Martian rocks contain jarosite minerals believed to have formed in the presence of water. - Gully systems on the walls of impact craters were carved by melt water. - High mesa islands in drainage channels indicate they were carved and shaped by erosion and depositional processes.
Which of the given statements are true of the polar caps on Mars? Mark all that apply.
- composed at least partly of frozen water - different sizes and temperatures in Northern and Southern caps
Approximately 80% of infrared (IR) radiation emitted by Earth is trapped by greenhouse gases, which causes the warming of Earth's atmosphere known as the greenhouse effect. Even though nitrogen (N2) and oxygen (O2) make up approximately 99% of the atmosphere, they do not contribute to the greenhouse effect. However, carbon dioxide (CO2) is a major contributor. Why does CO2 contribute to the greenhouse effect, whereas N2 and O2 do not?
CO2 is capable of absorbing infrared radiation, whereas N2 and O2 are not.
The greenhouse effect
Does not generate heat; it slows heat loss to space.
Match each description to the appropriate category according to whether it describes the atmosphere of Earth, Mars, or both Earth and Mars.
EARTH: - atmosphere is 78% nitrogen - pressure high enough for liquid water MARS: - atmosphere is 95% carbon dioxide - weakest greenhouse effect - dust storms in atmosphere can engulf entire planet - sky appears brownish due to dust content of atmosphere BOTH EARTH AND MARS: - some of the gas in the atmosphere came from geological activity
Classify the characteristics as describing the atmosphere of Earth or Venus.
EARTH: - atmosphere is mainly nitrogen - water can exist as a solid, liquid, or gas VENUS: - atmosphere is mainly carbon dioxide - runaway greenhouse effect - clouds shroud entire planet - sky has a yellowish tint due to absorption of sunlight - highest atmospheric pressure among terrestrial planets
Classify the physical characteristics of Mars by how they compare to Earth.
GREATER THAN EARTH: - orbital period ABOUT THE SAME AS EARTH: - rotational period - axial tilt LESS THAN EARTH: - planetary mass - atmospheric pressure - magnetic field
Venus had a runaway greenhouse effect, but Earth does not because
Venus has more carbon dioxide in its atmosphere.
Which is a major reason that Venus has such a dense carbon dioxide atmosphere today, as compared to the atmosphere of the Earth?
Venus is extremely arid.
Volcanoes on Mars are enormous because
the lack of plate tectonics means that volcanoes stay over a "hot spot" for billions of years.