Unit 2
How would you describe the rotation of Uranus?
Its rotation axis is tilted so that sometimes its poles almost directly face the Sun.
Venus's orbital distance from the Sun is 0.72 AU. How long does it take for Venus to complete one orbit around the Sun, compared to Earth?
Less than an Earth year; Venus orbits at a faster speed and has a shorter distance to trave
This has to do with the force of gravity on Mars' surface compared to the force of gravity on Earth.
Mars has a mass that is 1/10th the mass of Earth and a radius that is 1/2 the radius of Earth. This makes the force of gravity on the surface of Mars smaller than the force of gravity on the surface of the Earth, as shown in the image there."
Based on current evidence and understanding, what is the composition at the center of Neptune?
Neptune has a solid, rocky core
What evidence do we have that suggests Mars was once much wetter than it is today?
Outflow channels on the Martian surface and evidence for subsurface water ice.
What was Kepler's First Law?
Planets revolve around the sun in elliptical orbits with Sun at one focus of the ellipse
One of these features is impact craters.
Since you've learned about the Moon, I'm sure you know that craters are often the result of impacts with asteroids and other smaller solar system bodies which have orbits that bring them in direct collision with planets and moons.
The distribution of craters on Mars can be best described as:
The Southern Hemisphere has numerous craters and the Northern Hemisphere has few.
How does the Sun appear to move across the sky, viewed from the surface of Venus?
The Sun crosses the sky from the western horizon to the east.
Which type of lunar surface — the maria or the highlands — is relatively young compared to the other?
The dark lunar maria are younger than the bright highlands.
The Huygens probe saw bright and dark regions on the surface of Titan, and eventually descended through Titan's atmosphere to land on its surface. What are these dark and bright regions on Titan?
The dark regions are hydrocarbon mixtures and the bright areas are water-ice.
What general conclusion can we draw about the history of Martian geology?
The southern hemisphere with its highlands and craters are much older surfaces than the crater-deficient northern hemisphere with its lowlands.
From the Apollo astronauts' descriptions, what is the lunar surface physically like?
The surface is covered with fine dust.
At the same time, radiometric dating of the some of the rocks on Mars shows that they were solidified from molten lava as recently as 180 Myr ago, which can be described as 'the recent past' compared with the age of the solar system.
The white cloud is likely to be a volcanic plume - mixture of particles and gas emitted by an eruption. So some of these volcanoes show potential for eruption, although it is safe to assume, given what we know of the geology of Mars, that the planet is pretty much dormant as far as volcanic activity goes.
Which of the following phenomena are associated with magnetic fields of planets?
aurora
Saturn's rings are made primarily of...
chunks of dusty water-ice crystals
A comet's nucleus is composed of...
dust, dry ice, and water ice.
Pluto is presently considered...
dwarf planet, one of many among the trans-Neptunian objects.
The best opportunity to send spacecraft from Earth to Mars comes around
every 26 months, when the alignment of Earth and Mars in their orbits around the Sun allows spacecraft to travel between the two planets using the least amount of energy.
Comparing Mercury to the Earth's Moon, ...
they both have little atmosphere and a similar cratered surface.
Why are Uranus's rings darker in color than Saturn's or Jupiter's?
they have a lot of carbon/soot-like material in them.
Mars is the fourth planet from the Sun. It is similar to Earth in many ways. The duration of day and night on Mars is very close
to the duration of day and night on Earth. Mars also has a variety of landforms, many of which are similar to ones found on Earth.
Which of the following is true about Neptune?
ts atmosphere's composition is most like Uranus and its rings are like those of Uranus and Jupiter.
What was the "KT event?"
A large asteroid impact about 65 million years ago, with after effects leading to the decline of many forms of life on Earth, notably large ones like the dinosaurs.
A meteor shower can occur when...
Earth's orbit crosses a trail of debris left behind from a passing comet
How long does it take for Neptune to complete one orbit around the Sun, in terms of the time it takes for Earth to complete one orbit around the Sun (1 Earth year)?
164 Earth years.
Which of the features labeled (using arrows) are likely to be volcanic mountains? Use the altitude scale on the bottom left of the image to translate the color-coded information given in the map.
A: The ones pointed by the white arrows.
Consider those last two images. What general conclusion can we draw about the history of Martian geology?
A: The southern hemisphere with its highlands and craters are much older surfaces than the crater-deficient northern hemisphere with its lowlands.
What kind of atmosphere does the planet Mercury have?
An atmosphere that is thinner than Earth's.
The color-coding on this image is indicative of the elevation of the terrain around different parts of the planet. From the information presented in the image, it can be concluded that:
B: The northern hemisphere of Mars tends to lie lower than the average surface level. C: The southern plains are at a higher-than-average elevation.
Why do the planets orbit the Sun in close to the same plane?
Because they all formed in a disk around the early Sun and there was little material outside of that disk.
In the image of the Moon shown, below, identify which of the labeled regions correspond to maria and which ones correspond to terra, consistent with early astronomers' nomenclature.
C, B, E are terra; A, D and F are maria.
The mass of Saturn is equivalent to approximately how many Earth masses?
C: 100
How would the inflated landing module bounce if it were dropped onto the surface of Earth from the same altitude as it was on Mars?
C: It would bounce lower and fewer times than it did on the surface of Mars.
The distribution of craters can be best described as:
C: The Southern Hemisphere has numerous craters and the Northern Hemisphere has few.
What was Kepler's Third Law?
C: The square of the time period for an orbit of a planet is proportional to cube of its average distance from Sun (in other words P2 is proportional to a3).
Which best describes the appearance of a comet?
Comets develop a tail only when they get closer to the Sun in their orbits
satellites orbiting Mars are intended to investigate. This wide-angle image of a Martian volcano was acquired in March 2002 by the Mars Global Surveyor satellite.
Craters (marked with the red ellipses) can be seen right on top of some of the volcanic mountains. If these volcanoes had been active in the recent past, the depressions of the impact craters would have been filled with lava flows and the crater impressions would have been erased. The presence of craters close
What is known about the formation of Valles Marineris?
Different parts of Valles Marineris were shaped by different kinds of geological processes and NOT a single process.
Saturn is about 10 times as far from the Sun as Earth is (a = 10 AU, roughly). About how many times does Earth orbit the Sun in the time it takes Saturn to orbit just once?
E: About 30.
How does Pluto's mass compare with that of Earth's Moon?
Earth's Moon is roughly 7 times as massive as Pluto.
How can we tell the Moon does not have a substantial atmosphere?
If the Moon had an atmosphere, it would scatter sunlight in all directions and the lunar sky would look bright.
Each chemical compound has a unique color. By looking at these samples of chemical compounds, identify the compound that permeates the surface of Mars that gives the Martian soil its distinctive color.
Iron Oxide
What chemical compound gives the Martian soil its distinctive color?
Iron Oxide
Which of the following is/are caused by dense atmospheres?
It absorbs and scatters light, Atmosphere makes planetary surfaces warmer than they would be otherwise, Atmosphere distributes heat around a planet.
Which of the following could be the reason that Mars has only a thin atmosphere?
The gravity on Mars was insufficient to hold a thick atmosphere and hence the gases in the atmosphere escaped over time.
Why did astronauts walk on the surface of Moon with slow hops?
The gravity on the Moon is smaller than the gravity on Earth.
Which of these observations was used to prove that the rings of Saturn are not a single solid sheet?
The orbital speeds of the outer parts of the ring were smaller compared to the inner parts.
The development of ways to deploy robotic rovers on the Martian surface was a great engineering and technological feat.
The rovers (1) Sojourner in 1996 (2) Spirit and Opportunity in 2004 used smart design techniques for touching down safely on the Martian surface. Sojourner, Spirit and Opportunity were robots run on solar power that trekked across the Martian surface, conducting field geology and making atmospheric observations for many months.
What is a consequence of tidal locking?
The same side of a planet can be facing its parent star at all times.
Which of the following best describes how the sky would appear for someone standing on the surface of Mercury?
The sky would appear black (with stars visible) since Mercury has next to no atmosphere.
What would happen if the ozone layer were completely destroyed?
Ultraviolet radiation from the Sun would get through the atmosphere and cause damage to life.
Which of the following is true about Venus?
Venus has a very slow speed of rotation, Venus' day-night cycle is longer than its year, Venus is closer to the Sun than Earth is
Why is a day/night cycle on Venus longer than its year?
Venus' rotation time is very long compared to the time it takes to go once around the Sun.
Which of the following does Kepler's Second Law support?
When a planet is closer to the Sun, its speed is greater than when it is farther away.
Which of the following scenarios describes 'tidal locking'?
When the time it takes for an object to complete one rotation on its axis becomes equal to the time that it takes to revolve (complete one orbit) around another.
As was explained a while ago, gravity on Mars is substantially smaller compared to gravity on Earth. Because of this low gravity, Mars has NOT succeeded in holding on to a thick atmosphere.
Without a thick atmosphere, the planet has no way of regulating its temperature. As the orbit of the planet is far away from the Sun compared to Earth, not enough of Sun's radiation gets to it. A result of this is that the average surface temperature is about -20 degrees centigrade, with a minimum of somewhere around -140 degrees centigrade -
The Greenhouse effect on Venus ..
is stronger than it is on Earth
What chemical compound(s) gives Uranus its blue color?
methane
Volcanoes on Venus...
produce very large lava flows that cover at least 85% of the planet's surface.
Like the Moon, Mars has plenty of
raters on its surface which are easily distinguishable. Some of the craters are as big as a few hundred kilometers, though many are smaller."
The material in a meteorite is...
roughly as old as the Solar System.
a high crater density indicates
that the southern highlands are old and have been relatively unchanged by geological activity. During the heavy bombardment phase in the early history of the solar system, Mars (like the other planets of the solar system) was constantly bombarded by asteroids and other rocks from space.
What causes some Kuiper Belt objects to become short-period comets?
the gravity of the giant planets like Uranus and Neptune throw them into orbits that take them into the inner Solar System.