Caltech Astronomy Public Lecture Series - The History of the Solar System - Katherine de Kleer - 12/05/2025

What do we know about our early solar system and how the planets formed? What can asteroids and meteorites reveal about our cosmic origins? Join us for a 30-minute lecture about the history of our solar system followed by a panel Q&A consisting of several astrophysicists to answer your questions about astronomy and space science. Timestamps and description below: 00:00 Announcements 6:52 Introduction to Presenter 9:14 Solar System Presentation 46:10 Solar System Q&A 46:30 "What is the origin of the water on the Earth?" 48:32 "Did the water in the early solar system accrete on the Earth?" 50:18 "Why was the Sun created?" 52:50 Intermission 59:15 Q&A Panel Introductions 1:02:16 "How are comets and asteroids different?" 1:03:31 "What is the orbit of the asteroid belt?" 1:05:39 "What happens to planets ejected from our solar system?" 1:08:25 "What is the frequency of impacts from asteroids?" 1:11:31 "How do we measure the rate of impacts from asteroids?" 1:13:54 "If you accelerate one end of a wormhole to near c, can you see infinity?" 1:17:22 "Did something disrupt the protoplanetary systems with hot jupiters?" 1:19:37 "What is the process that forms the regolith (lunar soil)?" 1:22:22 "Can we use isotope measurements to identify the source of the Earth's water?" 1:25:10 "Are the sednoids rejects of the inner solar system?" 1:25:50 "What changed about the early solar system that led to the blowout of gas?" 1:29:08 "Did the Earth's magnetic field enable gas to settle on the Earth?" 1:31:09 "Can the Kuiper Belt block objects from traveling through it?" 1:35:03 "Can there be 'dark photons' that interact with dark matter?" 1:39:16 "How are rocks formed in the outer solar system without volcanoes?" 1:43:45 "How did the Oort Cloud form as a shell when the protoplanetary disk is a plane?" 1:45:13 "What defines the minor planets?" 1:47:02 "How are dwarf planets made?" 1:48:21 "How is the water on Earth made?" 1:51:52 "Does alien life exist in the universe?" 1:55:11 Concluding Remarks Title: The History of the Solar System: Insights from JWST Observations of Asteroids Lecturer: Katherine de Kleer Abstract: Earth and the other planets in our Solar System were born 4.5 billion years ago out of a disk of dust and gas orbiting our infant Sun. Some of the big open questions in this field are how, where, and when that dust coalesced into what became the precursor objects to our planets and then the planets themselves. Answering these questions requires a multi-pronged approach: we look at planetary systems like ours forming around other stars to see this process in action, and we study the leftover fragments from this time period in our own Solar System: asteroids and meteorites. Using the James Webb Space Telescope (JWST) and other observatories, we can identify the detailed composition of asteroids, which are made up of the same materials that formed our planets long ago. Such observations give us a new window into the early history of our Solar System.