We’re Going Back to Venus

Episode Summary

Executive Summary: This episode centers on NASA’s long-awaited return to Venus with two complementary Discovery missions—DaVinci+ and Veritas—plus ESA’s Envision, making a three-mission “armada” to study Venus’s atmosphere, geology, and evolution. Jim Garvin and Sue Smrekar describe mission design, instruments, launch timelines, international partnerships, and how the trio could reveal volcanism, tectonics, water history, and Venus’s relevance to Earth and exoplanets.

Main Topics: NASA’s Venus mission selections: Garvin and Smrekar react to being selected for DaVinci+ and Veritas after years of proposals, emphasizing the emotional weight of the call and the significance of returning to Venus after a long U.S. drought. Mission architectures and instruments: The guests explain how DaVinci+ will probe the atmosphere and surface chemistry during descent while Veritas will map Venus’s surface and gravity from orbit using radar and gravity science. International and cross-center collaboration: Both missions depend on broad partnerships across NASA centers, universities, Lockheed Martin, and international agencies including Germany, Italy, France, and ESA. Science questions: volcanism, tectonics, water, and interior structure: The conversation focuses on whether Venus is still volcanically active, whether subduction or plate tectonics exists, how much water remains in the planet, and what the interior structure reveals about its missing dynamo. Venus as an exoplanet analog and Earth’s twin: The guests argue Venus is the best nearby laboratory for understanding rocky-planet evolution, climate runaway greenhouse processes, and the interpretation of Venus-sized exoplanets. Planetary exploration context and space news: Host Matt Kaplan and Bruce Betts briefly cover Virgin Galactic and Blue Origin milestones, Ingenuity’s ninth flight, the first spacewalk outside China’s new station, and space trivia about married astronaut pairs and Venus history.

Key Arguments: Venus has been neglected for decades, and the new missions finally give scientists a modern way to answer fundamental questions about its evolution. DaVinci+ and Veritas are designed to be complementary: one provides atmospheric/descent chemistry and local ground truth; the other provides global radar/topography and gravity context. Modern instrumentation and onboard processing make it possible to achieve much higher resolution and data compression than Magellan, enabling a major leap in Venus science. Detecting recent or active volcanism on Venus is difficult but possible with the right spectral and radar measurements, especially repeat-pass interferometry and atmospheric chemistry. Venus’s interior structure and lack of a dynamo may be linked to its thermal state, crustal properties, and water content, making gravity and descent measurements crucial. Studying Venus helps explain how Earth-like planets evolve, including whether plate tectonics or subduction can start on rocky worlds and whether habitable conditions could persist. The missions are not just U.S. efforts; international collaboration and shared instruments are essential to their success and scientific reach.

Data Points: Venus launch timing: ~2028 (planned for both U.S. missions) - Smrekar said the missions were selected but need a longer planning window before launch. DaVinci entry/descent/landing timing: early 2031 - Garvin described one studied launch option consistent with NASA guidelines. Radar mapping improvement: 100x better topography resolution - Smrekar compared Veritas to Magellan’s topographic performance. Image data improvement: 10x better than Magellan - Smrekar said Veritas image data should be an order of magnitude better. Onboard data reduction: 1000-fold lossless compression - Veritas uses onboard processing to reduce data volume before downlink. Surface resolution example: 12–25 km per pixel (Magellan), vs. meters-scale features with Veritas - Used to illustrate how much more detail the new radar will reveal. Vertical resolution: 6 meters - Smrekar said Veritas’s surface vertical resolution will be about six meters. Gravity science precision: ±75 km estimate for core size - Garvin said DaVinci’s gravity science could constrain Venus’s core size to this range. Atmospheric descent rate: 10–12 m/s terminal velocity - Garvin described the final descent phase of the probe. Free-fall segment: last 40 km - Garvin said the probe will freefall after parachute release. Venus atmospheric dimensions: 450 million square kilometers - Garvin cited the immense area Veritas will help map. Relative rocky material in solar system: Venus 41%, Earth 43–45% - Smrekar used this to argue the two planets are the most important rocky-composition comparison case. InSight result publication: later that month - Smrekar noted first precise InSight interior results were due in Science soon. Mariner 4 flyby: 1965 - Bruce Betts’ space history segment. Apollo 11 Moon landing: 1969 - Bruce Betts’ space history segment. Apollo-Soyuz launch/connection: 1975 - Bruce Betts’ space history segment. Viking 1 Mars landing: 1976 - Bruce Betts’ space history segment. New Horizons Pluto flyby: 2015 - Bruce Betts’ space history segment. Venus contest deadline: Wednesday, July 21 at 8 a.m. Pacific - Listeners were asked to identify the first successful Venus orbiter.

Pivotal Quotes: "You're going to Venus." — Thomas Zurbuchen (quoted by hosts): The phone call notifying the principal investigators that their missions had been selected. "We are all going back to Venus." — Matt Kaplan: Host framing the broader significance of NASA and ESA mission selections. "Venus is the sister we didn't know we lost or had, that we better get to know." — Jim Garvin: Garvin describing Venus as a crucial twin for understanding planetary evolution.

Implications: The Venus program is entering a new era: three missions should deliver coordinated atmospheric, geologic, and gravitational data that could transform understanding of rocky planets, climate evolution, and habitability—on Venus, Earth, and exoplanets.