Which is these facts is NOT explained by the nebular theory? O There are two main types of planets: terrestrial and jovian O Existance of comets and asteroids O Planets orbit in the same direction and plane O Number of planets of each type (4 terrestrial and 4 jovian)

1. Which of the outer planets have compositions dominated by the "ices" ingredient? Check the correct two. 2. Which of the outer planets have compositions dominated by the "gases" ingredient? Check the correct two.  3. Most of the spaceflight missions to the outer planets have been flyby missions, but two of them were orbiters. Which of these two spacecraft orbited giant planets? Check the correct two. (Hint: An orbiter might do a flyby of one planet and then go on to orbit a different planet.) 4. Jupiter's mass is how many times larger than the Earth's? Just type a number, no words or any other extra stuff. 5. Which of the outer planets has extreme seasons, with its rotational axis being tilted so much that it is practically in the plane of its orbit?

How many impacts would you expect to strike a 100m2 region in one hour during Earth’s formation, assuming that Earth grew to its present size in 10 million years from particles averaging 100 grams each? (Hint: Assume that Earth had its current radius of 6378km.) (Notes: The surface area of a sphere is 4pir2 ; 1yr=3.2x107 .)   a. About 1300.     b. About 13 .     c. About 13,000.     d. About 130

4) Science fiction movies often portray asteroid belts as crowded, dense regions that require spaceships to maneuver quickly to get through them. In this problem, we will calculate the fraction of volume in an asteroid belt that is actually occupied by asteroids. a) If there are 300,000 large asteroids between 2 and 3 AU from the Sun, and each asteroid is assumed to be spherical with a radius of 100 km, determine the total volume occupied by asteroids in this region. Recall that the volume of a sphere is given by the equation V = 4TR³ /3. b) Let's assume the region in which these asteroids orbit is an annulus with an inner radius of 2 AU, an outer radius of 3 AU, and a thickness of 2Ro. Determine the volume of this region. Recall that the area of a circle is given by the equation A = TR². Here are two conversions that you'll need: 1 AU = 1.496 × 108 km and 1 Ro = 6.955 × 105 km. c) What is the ratio of the volume occupied by asteroids to the volume of the asteroid belt (i.e., the…