14. The grant collision hypothesis Involves an extremely unlikely event, In that all of the conditions-like the size and trajectory of the collider-must be just right to produce Earth's Moon. Is this extreme unlikelihood a DISadvantage of the hypothesis? 15. Sample return missions are rare; why? Do you think the Information gained would be worth the effort? 16. Exoplanets are planets orbiting stars other than our Sun. Some of these exoplanets are called "hot Jupiters"; these are massive gas planets orbiting close to their parent stars where only terrestrial planets should be. Does the existence of hot Jupiters make false the standard model of planet formation? Part VII -Further Research Extend your knowledge! Refer to textbooks, course notes, or other published materials on planetary science to respond to the following questions. Questions 17. What evidence Is there for (I) captured moons, and (II) moons that accreted around other planets In our solar system: 18. What other sample return missions have there been? What others are In the planning stage? 19. How Do proplyns In the Orion star formation region support the standard model of planet formation? One proposed solution to the existence of hot Jupiters Is to modify the standard model for planet formation by Introducing a process called planet migration. What evidence Is there for planet migration within our own solar system