Question 3Which of the following is NOT required for the formation of a large nearly isotropic Oort cloud full of many small bodies, assuming the scenario that we discussed is the dominant mechanism? 1 pointA planet like Jupiter which is massive enough to scatter bodies out of the solar systemPassing stars which perturb the orbits of low perihelion, high semimajor axis objectsA smaller planet like Neptune to scatter icy bodies inward so they can be ejected by a more massive planet like JupiterA population of small bodies which is close enough to a planet to get scattered outwardMultiple stellar encounters to randomize the cometary orbits into an isotropic cloudAll of these are required

The Oort Cloud is believed to beGroup of answer choicesa flattened belt of cometary nuclei just beyond the orbit of Neptune.the circular disk of gas around the Sun's equator from which the planets formed.a spherical cloud of cometary nuclei far beyond the Kuiper Belt.the great nebula found just below the belt stars of Orion.a grouping of asteroids and meteoroids between the orbits of Mars and Jupiter.

1.Question 1Which of the following is the best explanation of why we have small bodies in the solar system?1 pointNearby planets caused the orbits of forming planetesimals to acquire high velocities and eccentricities, preventing run away growth and leading to shattering impacts.Planetesimal formation in the region of the asteroid and Kuiper belts was delayed until after the gas in the nebular disk had dissipated, preventing these objects from acquiring gassy envelopes.Insufficient mass existed in the region of the asteroid belt and Kuiper belt to allow full sized planets to form.The oligarchs that formed in the region of the terrestrial planets and the asteroid belt slowly merged over ~100 Myr and the oligarchs at the outer range of this region were excited by Jupiter enough to cause impacts to shatter the objects. A similar process took place in the Kuiper belt.Nearby planets caused excitation of the orbits of planets in the region of the asteroid belt and Kuiper belt and these planets collided and their fragments are now the small bodies.

Which of the following is the first thing that must happen in order for solar system formation to take place?Group of answer choicesdust particles must clump together until they are large enough for gravity to affect themprotoplanets must slam together in such a way that they stick togetherthe protoplanetary disc must start spinning and flattening out as a protostar forms at its corean ancient star must explode to provide the heavy elements necessary for planet formation

Which of the following is the best description of the formation of a giant planet with a massive core? (at least as described in the lectures!)1 pointPlanetesimals grow through gravitational focusing. Dynamical friction slows the motions of the largest objects leading to runaway growth of oligarchs, which are isolated from other nearby oligarchs. Gas slowly accretes onto the oligarch through an envelope until the pressures are too high to support the envelope and massive amounts of gas collapse making the gas giant.Planetesimals grow through gravitational focusing. Dynamical friction slows the motions of the largest objects leading to runaway growth of oligarchs, which are isolated from other nearby oligarchs. Large numbers of oligarchs merge over hundreds of millions of years, leading to a giant core.Gas slowly accretes onto the oligarch through an envelope until the pressures are too high to support the envelope and massive amounts of gas collapse making the gas giant.Planetesimals grow through gravitational focusing. Dynamical friction slows the motions of the largest objects leading to runaway growth of oligarchs, which are isolated from other nearby oligarchs. The gravitational pull of the oligarch quickly overcomes the rotational and pressure forces from the disk, causing rapid growth of the gaseous atmosphere.In a massive disk the force of gravity in a patch of the disk overcomes the pressure and rotational forces and the patch quickly collapses into a giant planet. The heavy materials sink to the bottom and form the core.Planetesimals grow through gravitational focusing. Dynamical friction speeds the motions of the largest objects leading to more frequent collisions and runaway growth of oligarchs, which are isolated from other nearby oligarchs. Gas slowly accretes onto the oligarch through an envelope until the pressures are too high to support the envelope and massive amounts of gas collapse making the gas giant.

What is the name of the theory describing how solar systems form?Group of answer choicesthe nebular theorythe big bang theorythe neo-planetary theorythe theory of relative formation Flag question: Question 2Question 2Tips1 ptsWhich of the following is the first thing that must happen in order for solar system formation to take place?Group of answer choicesdust particles must clump together until they are large enough for gravity to affect themprotoplanets must slam together in such a way that they stick togetherthe protoplanetary disc must start spinning and flattening out as a protostar forms at its corean ancient star must explode to provide the heavy elements necessary for planet formation Flag question: Question 3Question 3Tips1 ptsWhich of the following correctly describes the progression of objects involved in planet formation from smallest to largest?Group of answer choicesdust, planetesimals, clumps, protoplanets, planetsdust, clumps, protoplanets, planetesimals, planetsdust, protoplanets, clumps, planetesimals, planetsdust, clumps, planetesimals, protoplanets, planets Flag question: Question 4Question 4Tips1 ptsWhy is exploding an ancient star one of the steps of building a solar system?Group of answer choicesthat’s how you blast open a spot big enough in a nebula for planets to formthat’s how you provide enough energy and heat for planets to formthat’s how you provide the materials that you need for planets to formthat’s how you cause planets to spin around the sun Flag question: Question 5Question 5Tips1 ptsWhich force “slams” larger and larger chunks together in the last part of solar system formation?Group of answer choicesgravityinertiapressurestatic attraction Flag question: Question 6Question 6Tips1 ptsWhat is the main type of force responsible for the clumping of dust during the beginning stages of solar system formation?Group of answer choicesgravityinertiapressurestatic attraction Flag question: Question 7Question 7Tips1 ptsWhat is happening during the second stage of solar system formation?Group of answer choicesyou use gravity to form a spinning disk around a protostaryou use static to clump dust togetheryou explode an ancient star to get some heavy elementsyou use gravity to slam bigger and bigger objects together Flag question: Spacer Flag question: Question 8Question 8Tips1 ptsWhat does ‘A’ represent on the diagram above?Group of answer choicesStrong gravitational forceVelocityEarth's Orbit Flag question: Question 9Question 9Tips1 ptsWhat does ‘B’ represent on the diagram above?Group of answer choicesVelocityStrong gravitational forceEarth's Orbit Flag question: Question 10Question 10Tips1 ptsWhat does ‘C’ represent on the diagram above?Group of answer choicesEarth's OrbitStrong gravitational forceVelocity