ScienceAstronomyExoplanetsAstronomy Mod 15
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Astronomy Mod 15

Ileana Gray avatar Ileana Gray
25 July 2022
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33 test answers

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question
The depth of the dip in a star's brightness due to the transit of a planet depends most directly on:
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not:The size of the planet's orbit. or mass
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(Select all that apply.) When a system's eccentricity is zero:
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maybe: The radial velocity graph looks like a sine curve; all its peaks are symmetric Its orbits are circular.
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What is an extrasolar planet?
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a planet that orbits a star that is not our own Sun
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How did the Kepler mission detect Earth-like planets around other stars?
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not: By observing the spectrum of the planet. or By measuring the slight shift in position of the central star as it is tugged to and fro by the planet.
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Approximately how many exoplanet systems have been discovered to date?
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thousands
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The radial velocity technique only provides a measure of the minimum mass of a planet because:
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Only the motion of star directly towards or away from the observer is measured, not the full motion.
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How does the transit method detect exoplanets?
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By observing the slight dip in brightness of the central star as the planet transits.
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What are the two main differences between extrasolar planetary systems discovered to date and our Solar System?
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not: Extrasolar planets discovered so far tend to be bigger and denser than Jupiter.
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Which of the following statements about ozone in Earth's stratosphere is NOT true?
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The presence of ozone was crucial to the origin of life.
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When we analyze whether a world is a possible home to life, the key thing we look for is:
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The past or present existence of liquid water.
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What was the Cambrian explosion?
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a dramatic diversification of life that began about 540 million years ago
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Why didn't oxygen begin to accumulate in the atmosphere until approximately 1.5 billion years after life appeared on Earth?
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Oxygen produced by life was removed from the atmosphere by oxidation reactions with surface rocks; we see evidence for this in banded iron formations.
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Which of the following best describes how the Drake equation is useful?
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It helps us understand what we need to know in order to determine the likelihood of finding other civilizations.
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The oldest minerals on Earth are:
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zircons
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When did oxygen begin to accumulate in Earth's atmosphere?
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About 2 billion years ago.
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Approximately when is a waxing gibbous moon on your meridian?
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9pm
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Why can't Sagittarius be seen during the winter?
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In the winter, Sagittarius is only above the horizon during the daytime due to Earth's position in its orbit.
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Why do Uranus and Neptune have blue methane clouds but Jupiter and Saturn do not?
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Methane does not condense into ice in the warmer atmospheric temperatures of Jupiter and Saturn.
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Which of these dwarf planets lives in the Kuiper belt? Select all that apply.
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not: ceres
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Most of the planets discovered around other stars:
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are more massive than Earth and orbit very close to the star.
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Orbital resonances may contribute to the high eccentricities seen in exoplanet orbits.
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true
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(Select all that apply.) When a system's eccentricity is high:
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ts orbits are elliptical and very elongated The radial velocity velocity graph looks lopsided; its positive and negative peaks do not reach the same speed.
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The transit method most easily detects:
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not: Small planets in edge-on orbits around big stars.
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The only place outside of Earth where there is irrefutable evidence for ancient, microbial life is:
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nowhere
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In general, how does the size and location of a star's habitable zone depend on the star's mass?
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The less massive the star, the smaller and the closer in the habitable zone.
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What is a mutation?
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change in DNA sequence
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The galactic habitable zone is the location in the Milky Way where liquid water is thought to exist.
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false
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Which of the following describes a major danger of interstellar travel at near light speed?
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Atoms and ions in interstellar space will hit a fast-moving spacecraft like a flood of dangerous cosmic rays.
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Why do some scientists say that the Moon may have been important for the evolution of human life?
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It stabilized Earth's axis tilt and prevented large climate changes.
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Approximately when is a new moon on your meridian?
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noon
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Stars rise in the east and set in the west for everyone living in the southern hemisphere.
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true
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What substance generates Neptune's magnetic field?
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not: hydrogen
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Astronomers have decided that, rather than being a planet, Ceres is really just a large member of:
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Asteroid belt.