The two most important processes in heating the interiors of the terrestrial worlds are __________.(1) heat deposited by the process of formation; (2) heat released by radioactive decay
Earth has been gradually warming over the past few decades. Based on a great deal of evidence, scientists believe that this warming is caused by _____.human activities that are increasing the concentration of greenhouse gases in Earth’s atmosphere
The terrestrial planets are made almost entirely of elements heavier than hydrogen and helium. According to modern science, where did these elements come from?They were produced by stars that lived and died before our solar system was born.
Which of the following statements about asteroids, Kuiper belt objects, and Oort cloud objects is true?Objects in the asteroid belt and Kuiper belt orbit the Sun in nearly the same plane as the planets, but objects in the Oort cloud do not.
A rock found on Earth that crashed down from space is called _________.a meteorite
What atmospheric constituent is responsible for the blue color of Uranus and Neptune?methane
The processes responsible for virtually all surface geology are _________.impact cratering, volcanisms, tectonics, and erosion
Which of the following is a general characteristic of the four jovian planets in our solar system?They are lower in average density than are the terrestrial planets.
When a comet passes near the Sun, part of it takes on the appearance of a large, bright ball from which the tail extends. This part is called _________.the coma
typical meteor is created by a particle about the size of a _________.pea
According to current evidence, Pluto is best explained as ______a large member of the Kuiper belt
what is true about comets in our solar system?-All comets orbit the sun
-All comets are icy in composition.
-All comets are leftover planetesimals that originally condensed beyond the frost line in the solar nebula.
When we say that jovian planets contain significant amounts of hydrogen compounds, we meanmethane, water, ammonia
According to our theory of solar system formation, what are asteroids and comets?leftover planetesimals that never accreted into planets
Based on all we know about the terrestrial worlds, what single factor appears to play the most important role in a terrestrial planet’s geological destiny?its size
In general, which of the following are affected by a magnetic field?charged particles or magnetized materials (such as iron)
Which statement about Io is true?It is the most volcanically active body in our solar system.
Among discovered meteorites, we have found some with all the following origins EXCEPT _________.being a fragment from Comet Halley
Which of the following best describes the internal layering of Jupiter, from the center outward?core of rock, metal, and hydrogen compounds; thick layer of metallic hydrogen; layer of liquid hydrogen; layer of gaseous hydrogen; cloud layer
Which of the following does NOT provide evidence that Mars once had abundant liquid water on its surface?the presence of canali, discovered in the late 1800s by Giovanni Schiaparelli and mapped by Percival Lowell
According to modern scientific dating techniques, approximately how old is the solar system?4.5 billion years
Overall, Jupiter’s composition is most like that of _________.the sun
In essence, the nebular theory holds that _________.our solar system formed from the collapse of an interstellar cloud of gas and dust
Suppose we represent Earth with a basketball. On this scale, most of the air in Earth’s atmosphere would fit in a layer that is _________.about the thickness of a sheet of paper
Suppose you view the solar system from high above Earth’s North Pole. Which of the following statements about planetary orbits will be true?All the planets orbit counterclockwise around the Sun.
Which moon has a thick atmosphere made mostly of nitrogen?titan
The jovian planets in our solar system are _________.Jupiter, Saturn, Uranus, and Neptune
Which direction do a comet’s dust and plasma tails point?generally away from the Sun
Which of the following types of material can condense into what we call ice at low temperatures?hydrogen compounds
Which of the following is the most basic definition of a greenhouse gas?a gas that absorbs infrared light
The planet in our solar system with the highest average surface temperature is _________.Venus
According to our theory of solar system formation, what three major changes occurred in the solar nebula as it shrank in size?It got hotter, its rate of rotation increased, and it flattened into a disk.
What is the importance of the carbon dioxide (CO2) cycle?It regulates the carbon dioxide concentration of our atmosphere, keeping temperatures moderate.
Suppose you could float in space just a few meters above Saturn’s rings. What would you see as you looked down on the rings?countless icy particles, ranging in size from dust grains to large boulders
What is the giant impact hypothesis for the origin of the Moon?The Moon formed from material blasted out of Earth’s mantle and crust by the impact of a Mars-size object.
What do we mean by the frost line when we discuss the formation of planets in the solar nebula?It is a circle at a particular distance from the Sun, beyond which the temperature was low enough for ice to condense.
Which moon is considered likely to have a deep, subsurface ocean of liquid water?Europa
Suppose we use a baseball to represent Earth. On this scale, the other terrestrial worlds (Mercury, Venus, the Moon, and Mars) would range in size approximately from that of _________.a golf ball to a baseball
The asteroid belt is located _________.between the orbits of Mars and Jupiter
Which of the following statements about the moons of the jovian planets is NOT true?Most of the moons are large enough to be spherical in shape, but a few have the more potato-like shapes of asteroids.
What observational evidence supports the idea that Mercury once shrank by some 20 kilometers in radius?the presence of many long, tall cliffs