Solar Probe Plus Will Fly to the Sun

Episode Summary

Executive Summary: This Planetary Radio episode centers on NASA’s Solar Probe Plus mission, which aims to fly within 4 million miles of the Sun to directly sample the corona and solar wind. The show also covers robotic exploration wins, criticisms of NASA-focused media narratives, an asteroid near-miss, and a skywatch/trivia segment with Bruce Betts.

Main Topics: Solar Probe Plus: mission to the Sun: NASA’s planned probe will use a heat shield and in-situ measurements to survive extreme solar conditions and study the corona and solar wind up close. Robotic exploration as a 'golden age': Emily Lochtawala argues that robotic missions are delivering extraordinary science and are often undervalued compared with human spaceflight. Media criticism and space narrative bias: Emily critiques a Discover Magazine piece for implying NASA had failed because of human-spaceflight problems, ignoring the success of robotic exploration. Human exploration advocacy: Bill Nye argues that public excitement is driven by humans in space and that future exploration should include people traveling to new destinations like asteroids and Mars. Asteroid near-miss and small-object detection: The episode notes two recently discovered asteroids passing Earth at close range, illustrating both the abundance of small objects and the challenge of finding them early. Night sky update and trivia contest: Bruce Betts provides observing tips, a contest winner, and a new question about the densest moon in the solar system.

Key Arguments: Solar Probe Plus will use direct, in-situ sampling rather than remote sensing, allowing scientists to measure particles, magnetic fields, electric fields, and waves in the corona without relying only on models. The Sun’s corona is paradoxically much hotter than the surface, and understanding why matters both for fundamental physics and for space weather effects on satellites and astronauts. The robotic exploration era is producing more missions, more data, and broader scientific return than ever before, even if public attention often goes to crewed programs. Human missions still matter because people inspire public interest and can drive ambitious exploration goals beyond Earth orbit. Small near-Earth asteroids are numerous and frequently missed until close approach; improved detection would reveal many more of them, likely on a daily basis. Media coverage that equates NASA mainly with human spaceflight can obscure the achievements of robotic exploration and misrepresent the state of the agency.

Data Points: Solar Probe Plus closest approach: 4 million miles from the Sun’s surface - Lika Guhathakurta describes the planned spacecraft trajectory Mercury distance from the Sun: 36 million miles - Used as a comparison for how much closer Solar Probe Plus will go Corona temperature: about 1,400°C / 2,600°F at the spacecraft environment; million-degree corona discussed - Heat shield and scientific motivation for the mission Sun surface temperature: 4,500 to 6,000°C - Contrast with the hotter corona Solar wind speed: about 400 kilometers per second - Described as the steady breeze the mission aims to understand Launch target: before 2018 - NASA’s hoped-for launch timeline for Solar Probe Plus STEREO milestone: February 2011 - Expected date when the spacecraft would allow a view of the far side of the Sun Jupiter opposition: September 20 - Bruce Betts’s skywatch update Contest winner: Thomas Helm of Tatsuno, Japan - Won for correctly identifying Crux as the smallest constellation Smallest constellation: Crux (Southern Cross) - Answer to the trivia question Largest constellation: Hydra at 1,303 square degrees - Listener correction/extra fact mentioned during the contest segment Asteroid proximity: double the distance of geosynchronous satellites - 2010 RF-12’s close pass by Earth Asteroid detection frequency: several times a year; potentially daily if capability improved - NASA scientist Lindley Johnson’s estimate Number of small inner-solar-system objects: tens of millions - Johnson describes their abundance

Pivotal Quotes: "We are in a golden age of space exploration." — Emily Lochtawala: Her defense of robotic missions and criticism of media narratives that dismiss NASA’s achievements "We got to get the space agencies around the world to get together and send people to exciting new places to make discoveries." — Bill Nye: His argument that human exploration is what captures public imagination and should continue "We don’t know what we don’t know." — Lika Guhathakurta: Her explanation of why Solar Probe Plus could produce unexpected discoveries

Implications: The episode frames robotic solar-system exploration as scientifically mature and underappreciated, while also arguing that future ambition depends on balancing robotic discovery with human missions. For listeners, it underscores both the urgency of space-weather research and the next frontier in understanding the Sun.