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23 Cards in this Set
- Front
- Back
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We are able to image the surface of most of the terrestrial planets and moons from the surface of the Earth. Why do we bother to send satellites to the planets? |
The resolution of our telescopes doesn't allow us to see fine details from Earth |
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What is the reason Mercury has essentially no atmosphere? |
Its mass is small, close to the Sun, escape velocity low |
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Mars, Venus, and Earth are much less heavily cratered than Mercury and the Moon. How is this explained? |
Mars, Venus, and Earth were geologically active for a longer period of time than Mercury and the Moon |
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What is the main reason that the Earth's interior is liquid today? |
decay of radioactive material |
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Present-day gradation on the surface of the Moon is primarily caused by what? |
impact cratering |
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Why is Mercury not volcanically active today? |
Mercury is very small |
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The length of time that it takes a radar signal sent from a spacecraft to bounce off planet's surface and return to the spacecraft indicates what? |
the distance the signal travled |
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Why are no planets found within 0.3 AU from the Sun? |
No materials in the solar nebula could condense that close to the Sun |
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The size and shape of an impact crater will be determined by? |
the speed of the impactor, size of impactor, and the presence or lack of an atmosphere |
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Which geologic process occurs at the same rate on all planets? |
impact cratering |
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Which terrestrial planet has the youngest surface? |
Earth |
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Which of the planet's fundamental properties has the greatest effect on its level of volcanic activity? |
size |
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What do we conclude if a planet has few impact craters of any size? |
other geologic processes have wiped out craters |
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The relatively few craters that we see within the lunar maria mean that? |
The impacts were formed by impacts that occurred after those that formed most of the craters in the lunar highlands |
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Whether or not a planet retains an atmosphere depends on what? |
the planet's mass, the composition of the atmosphere, and the temperature of the atmosphere |
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Earth and Venus have very similar masses and radii and yet their surface conditions are quite different. What is the primary reason for this? |
Venus is closer to the Sun than Earth |
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How is it that rock from a volcanic eruption on Mars could make it all the way to Earth? |
Mars has the largest volcano in the solar system- Olympus Mons- which can eject material at enormous velocities. The gravity of Mars is lower than Earth's due to its smaller mass and the thin atmosphere on Mars produces very little drag |
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Terrestrial planets |
Mercury, Earth, Venus, and Mars
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Characteristics of Terrestrial Planets |
Smaller size and mass
Higher density Mostly made of rock and metal Solid surface Few (if any) moons; no rings Closer to the sun Closer together Warmer surfaces |
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Jovian Planets |
Jupiter, Saturn, Uranus, Neptune |
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Jovian Planet Characteristics |
Larger size and mass
Lower density Mostly made of hydrogen, helium, andhydrogen compounds No solid surface Rings and many moons Farther from the sun Farther apart from each other Cool temperatures at cloud tops |
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Where is the main asteroid belt? |
between Mars and Jupiter |
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