Caltech Astronomy Public Lecture Series - Searching for Near-Earth Objects - Joe Masiero - 10/03/2025

How frequently do comets and asteroids pass near the Earth? How do we detect these objects and ensure they do not pose a threat to us? What can they teach us about the formation of the Solar System? Join us for a 30-minute lecture about near-earth objects, 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 8:00 Introduction to Presenter 9:50 Asteroids Presentation 39:54 Asteroids Q&A 40:08 "How do we know when we've identified 90% of all asteroids, when they are unknown?" 41:47 "If the comet hits the Moon, how will it change the Moon?" 42:58 "How do radar observations of asteroids help us to study them?" 44:58 "Why are asteroids hot?" 46:42 Intermission 53:39 Q&A Panel Introductions 57:02 "Will the universe keep expanding forever? How do we know it's expanding?" 1:00:45 "How would one detect asteroids around another star?" 1:03:53 "Can you explain how the DART mission tests planetary defense?" 1:05:20 "Why are there larger than normal diamonds in some asteroids?" 1:07:10 "Why is the asteroid belt between Mars and Jupiter and not elsewhere?" 1:08:37 "In infrared, why are the stars hotter than the asteroids?" 1:09:35 "Are there any updates on the new interstellar comet, 3I/ATLAS ?" 1:13:38 "Is our asteroid belt a common feature of planetary systems?" 1:17:28 "Can an asteroid belt be at other locations in planetary systems?" 1:19:18 "How is astronomy research continuing due to uncertainty in federal funding?" 1:23:47 "Will the universe ever stop its expansion and contract back on itself?" 1:27:34 "How do we know that simulation data is applicable to the real universe?" 1:31:17 "How will the new Roman and Rubin telescopes aid in your research?" 1:38:55 "How do manmade radio waves block our ability from seeing astronomical sources?" 1:44:12 "Do gravitational simulations of the asteroid belt become chaotic from so many bodies?" 1:46:30 "Is there evidence that the universe is inside of a black hole?" 1:48:14 "What is the universe expanding into?" 1:52:59 "Can quantum computing reveal information about locations beyond the observable universe?" 1:56:28 Concluding Remarks Title: Astronomy on our Doorstep: Searching for Near-Earth Objects Lecturer: Joe Masiero Abstract: Asteroids and comets in the inner Solar System are referred to as Near-Earth objects (NEOs) based on their proximity to Earth. These bodies, which formed at the birth of our Solar System almost 5 billion years ago, provide us with important insights about the history and evolution of our Sun and the planets. However, NEOs also pose a hazard to the Earth due to the possibility of collision. In this talk, I will discuss how astronomers discover NEOs, what techniques we use to understand them better, what we can do if we find one that poses the threat of impacting Earth, and the exciting future in store as the next-generation telescopes to study NEOs begin operation.