Return to Dimorphos: Looking forward to the Hera launch

Episode Summary

Executive Summary: This episode centers on the imminent launches of ESA’s Hera and NASA’s Europa Clipper, with a deep dive into Hera’s role as the post-DART planetary defense mission. Sarah Al-Ahmed interviews Hera project scientist Michael Coopers about the mission’s goals, instruments, trajectory, and scientific value, then Amber Trujillo explains NASA’s Runway to Jupiter style challenge for Europa Clipper. The segment closes with Bruce Betts on the possibility of a future DART-caused meteor shower and the broader significance of planetary defense.

Main Topics: Hera mission overview and launch timeline: The episode opens with excitement around Hera’s launch from Cape Canaveral on a SpaceX Falcon 9 and its long transit to the Didymos-Dimorphos system to study the aftermath of DART. Planetary defense and DART follow-up science: Michael Coopers explains Hera’s core purpose: to measure Dimorphos’ mass, characterize the impact crater or deformation, and refine asteroid deflection models for future planetary defense efforts. Small-body science and binary asteroid formation: The conversation broadens to what Hera can reveal about asteroid composition, binary formation, crater scaling, and how small bodies preserve clues to solar system history. CubeSats and instrument suite: The episode details Hera’s onboard and CubeSat payloads, including Juventas radar investigation of interior structure and Milani’s spectroscopy, as well as the primary spacecraft’s cameras, spectrometer, thermal imager, and laser. Europa Clipper launch culture and Runway to Jupiter: Amber Trujillo describes NASA’s style challenge encouraging creative, space-themed outfits and social-media participation tied to Europa Clipper’s launch. Future meteor shower from DART ejecta: Bruce Betts discusses the speculative possibility of a human-caused meteor shower in 2034 from DART ejecta, likely visible mainly in the southern hemisphere. Public engagement, advocacy, and launch watch parties: The Planetary Society promotes launch livestreams, member watch parties, advocacy for NASA funding, and audience participation through outfits, reviews, and community posts.

Key Arguments: Hera is essential because ground-based observations cannot uniquely determine what happened to Dimorphos after DART; only a close-up spacecraft can measure shape change, mass, crater formation, and surface alteration. The mission will improve planetary defense by turning DART’s qualitative success into quantitative guidance on impactor size, target response, and scaling laws for future deflection missions. Binary asteroids are scientifically important and possibly more common than current estimates suggest; Hera can help refine understanding of their prevalence and formation mechanisms. Small bodies are foundational remnants or fragments from solar system formation, so studying Dimorphos and Didymos also advances basic planetary science beyond defense applications. The CubeSats are valuable even if they do not land perfectly; unexpected interactions with the surface will still provide scientific information. The potential DART-caused meteor shower is speculative but scientifically plausible; if it occurs, it would likely be a subtle enhancement rather than a major shower. NASA’s style challenge is framed as a creative public-engagement tool that helps people connect emotionally and visually with Europa Clipper’s science.

Data Points: Hera launch date: October 7, 2024 - Scheduled launch of ESA’s Hera mission Hera launch window: October 7–27, 2024 - Launch window discussed during the interview Hera launch vehicle: SpaceX Falcon 9 - Rocket carrying Hera from Cape Canaveral Hera mission duration at target: 6 months - Nominal science operations around the Didymos-Dimorphos system Distance for characterization orbit: 10 kilometers - At this altitude Hera gets about 1 meter per pixel resolution Distance for close flyby: 1 kilometer - At this altitude Hera can reach about 10 centimeters per pixel resolution Escape velocity of system: 40 centimeters per second - Hyperbolic arcs are used because stable Kepler orbits are not practical Observation interval for maneuvers: Every 3 to 4 days - Hera will perform regular maneuvers to stay near the asteroid system Dimorphos size: About the height of the Great Pyramid of Giza; ~150 meters - Bruce Betts’ comparison of Dimorphos’ scale Binary asteroid prevalence: ~15% - Estimate discussed for known small-body systems, possibly a lower bound DART impact date: September 2022 - DART altered Dimorphos’ orbit around Didymos Hera launch site: Cape Canaveral, Florida - Launch location for Hera Europa Clipper launch date: October 10, 2024 - Scheduled launch referenced in the episode Europa Clipper launch time: 12:31 p.m. Eastern / 9:30 a.m. Pacific / 16:31 UTC - Watch party timing for Europa Clipper Hera launch time: 10:45 a.m. Eastern / 7:45 a.m. Pacific / 14:45 UTC - Planetary Society watch party timing for Hera Potential DART meteor shower timing: 2034 - Speculative date for a possible future meteor shower Potential meteor shower visibility: Mostly southern hemisphere - Bruce Betts says any shower would likely be visible there Potential meteor size: Up to softball-sized - Largest speculative ejecta fragments that could produce bright meteors

Pivotal Quotes: "we have successfully impacted Dimorphos, the moon of Asteroid Didymus" — Michael Coopers: Explaining the reason Hera is returning to the asteroid system "we will know the quantitative outcome, which helps us really for the future to not only to repeat it, but kind of also to scale what size of impactor you need for a given target" — Michael Coopers: On Hera’s value for future planetary defense planning "this would be the first time we have rocky stuff that we blasted off something to do that" — Bruce Betts: Describing the possibility of a human-caused meteor shower from DART ejecta

Implications: Hera could turn asteroid-deflection from a proof of concept into an operational science, improving future planetary defense. Europa Clipper adds public excitement and engagement, while both launches highlight international cooperation and the growing maturity of deep-space exploration.