Mastery Astronomy Assign 4-Chapters 6&10
The dwarf planet Eris was discovered in 2005, orbiting the Sun at an average distance about twice that of Pluto. In which of the following ways do Pluto and Eris differ from the terrestrial and jovian planets in our solar system?
*Both Pluto and Eris are smaller than any of the terrestrial planets. *Both Pluto and Eris travel in more elliptical orbits than any of the terrestrial or jovian planets. *Both Pluto and Eris are less massive than any of the terrestrial or jovian planets.
What are the two current major approaches to detecting extrasolar planets indirectly?
*Doppler method *Transit method
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.
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.
Match the star's positions at points 1, 2, 3, and 4 in the plot with the descriptions below.
Point 1: farthest from earth Point 2: headed straight toward earth Point 3: closest to earth Point 4: headed straight away from earth
Which planet is approximately halfway between Pluto's orbit and the Sun?
Uranus, the seventh planet from the Sun
The composition of the solar nebula was 98%
hydrogen and helium.
What substances were found within the inner 0.3 AU of the solar system before planets began to form?
rocks, metals, hydrogen compounds, hydrogen, and helium, all in gaseous form
What method has detected the most extrasolar planets so far?
the transit method
Explain how alien astronomers could deduce the existence of planets in our solar system by observing the Sun's motion.
*They could measure the small changes in position of the Sun to deduce the presence of our planets. *They could measure the small velocity changes of the Sun to deduce the presence of our planets.
Match the planet's positions at points 1, 2, 3, and 4 in the plot with the descriptions below.
Point 1: closest to earth Point 2: headed straight away from earth Point 3: farthest from earth Point 4: headed straight to eard earth
Assuming that other planetary systems form in the same way as our solar system formed, where would you expect to find terrestrial planets?
Terrestrial planets will likely be located nearer the planetary system's star than any jovian planets.
Listed following are statements that, based on our current theory of solar system formation, apply either to the formation of terrestrial planets or of jovian planets, but not both. Match these to the appropriate category.
Terrestrical Planets: *accreted from planetesimals of rock and metal *surfaces dramatically altered during the heavy bombardment Jovian Planets: *accreted from icy planetesimals *formed in regions cold enough for water to freeze *ejected ocy planetesimals that are now Oort cloud comets *formed in a region of the solar system with lower orbital speeds *large moons formed in surrounding disks of material
How would the plot change if the planet were more massive (but remained at the same orbital distance)?
The peaks and valleys would get significantly larger (greater positive and negative velocities) because of larger gravitational tugs.
How can gravitational tugs from orbiting planets affect the motion of a star?
The planet and the star both make orbits about a common center of mass. The star, being much larger than the planet, has a much smaller orbit. But it does move slightly.
What's the best explanation for the location of hot Jupiters?
They formed farther out like Jupiter but then migrated inward.
What is the giant impact hypothesis for the origin of the Moon?
What is the giant impact hypothesis for the origin of the Moon?
How long does it take the star and planet to complete one orbit around their center of mass?
about 4 days
What maximum velocity does the star attain?
about 50 m/s.
Where would you expect terrestrial planets to form in the solar nebula?
anywhere between 0.3 AU and the frost line
When we say that jovian planets contain significant amounts of hydrogen compounds, we mean all the following chemicals EXCEPT _________.
carbon dioxide
Which lists the major steps of solar system formation in the correct order?
collapse, condensation, accretion
Leftover ice-rich planetesimals are called
comets.
Planetary orbits are:
fairly circular and in the same plane.
Compared to terrestrial planets, jovian planets are __________.
more massive and lower in average density
What substances existed as solid flakes within the inner 0.3 AU of the solar system before planets began to form?
none
The jovian planets are thought to have formed as gravity drew hydrogen and helium gas around planetesimals made of __________.
rocks, metals, and ices
