Meet the AAS 248 Plenary Speakers: Dr. David Jewitt

Key Takeaways

• Discovered the Kuiper Belt in 1992, revealing thousands of distant objects
• Identified active asteroids in 2005, showing ice sublimation within the asteroid belt
• Proposes comet fragmentation via spin-up from asymmetric outgassing as primary death cause
• Studying interstellar interlopers (ʻOumuamua, Borisov, ATLAS) to redefine solar‑system boundaries

Pulse Analysis

David Jewitt’s name is synonymous with modern planetary science. In the early 1990s he and graduate student Jane Luu turned a tedious blinking‑image technique into a breakthrough, spotting the first Kuiper Belt object and proving that a vast, icy reservoir exists beyond Neptune. That discovery forced astronomers to rewrite textbooks on solar‑system architecture and sparked a wave of deep‑sky surveys that continue to map the distant frontier. Jewitt’s work exemplifies how persistence and clever use of modest technology can overturn long‑standing assumptions.

A decade later Jewitt’s team uncovered a second surprise: active asteroids—rocky bodies that emit comet‑like gas and dust. The James Webb Space Telescope later confirmed water‑ice sublimation on several of these objects, suggesting a possible source of Earth’s oceans. Simultaneously, Jewitt has championed a new model for comet demise, arguing that uneven outgassing spins nuclei apart long before volatile loss can erode them. Recent Hubble observations of comet 41P support this spin‑up hypothesis, offering a fresh perspective on why most comets vanish after only a few thousand years.

Now, at AAS 248, Jewitt turns his attention to interstellar interlopers—objects that traverse the solar system on hyperbolic trajectories. With only three confirmed visitors—ʻOumuamua, Borisov and the newly identified ATLAS—each displays distinct physical traits, challenging existing theories of planetary system ejection. By dissecting their composition and dynamics, Jewitt hopes to illuminate the processes that shape planetary systems galaxy‑wide. His broader message to emerging scientists is clear: pursue curiosity‑driven questions that push the known edge, rather than chasing incremental metrics. This philosophy not only fuels discovery but also ensures that astronomy remains an exploratory, rather than purely career‑oriented, endeavor.