2012 DA14--Coming Soon to a Planet Near You!

Episode Summary

Executive Summary: This episode centers on asteroid 2012 DA14’s close flyby, using NASA expert commentary to explain near-Earth object risks, detection methods, and future mitigation. It also spotlights Emily’s Earth-observation resource on Landsat imagery, the OSIRIS-REx mission to return an asteroid sample, and Bruce Betts’s skywatching updates and trivia, blending science communication with public engagement.

Main Topics: 2012 DA14 close flyby and hazard context (Priority: 5/5): The show’s main focus is the near-Earth asteroid 2012 DA14, its unusually close 2013 flyby, why it matters, and what it reveals about planetary defense and impact risk. NASA asteroid detection and characterization efforts (Priority: 5/5): NASA scientists describe how surveys, infrared observations, and radar track near-Earth objects, improve orbit estimates, and help assess the population of hazardous asteroids. OSIRIS-REx mission and asteroid sample return (Priority: 4/5): NASA’s upcoming mission to asteroid 1999 RQ36 is presented as both a science mission and a technology pathfinder for future asteroid operations and possible deflection work. Landsat Look Viewer and Earth-observation imagery (Priority: 3/5): Emily Loctawala highlights a web tool for browsing decades of Landsat imagery, showing how Earth’s surface changes over time and how to create shareable images. Asteroid origins, migration, and the Yarkovsky effect (Priority: 4/5): Speakers explain how asteroids move from the main belt into near-Earth space through resonances and subtle non-gravitational forces like sunlight-driven Yarkovsky drift. Night sky notes and Planetary Society community content (Priority: 2/5): Bruce Betts shares observing tips, a history note on Shoemaker-Levy/Eros, trivia about 2012 DA14, and listener mail, reinforcing the show’s outreach tone.

Key Arguments: 2012 DA14 is a noteworthy close approach because it passes inside geosynchronous satellite distance, making it a rare and scientifically useful event. Detecting small near-Earth objects requires sustained surveys; DA14 might not have been found a decade earlier, showing real progress but also remaining gaps. Infrared surveys like NEOWISE are effective because asteroids glow in heat and space-based telescopes can find objects inside Earth’s orbit more efficiently than ground-based systems. Radar observations from Arecibo and Goldstone provide precise orbital data plus shape and rotation details that are crucial for hazard assessment. OSIRIS-REx will return a primitive asteroid sample to Earth, helping answer major questions about solar system chemistry, organics, and water relevant to life’s origins. Understanding the Yarkovsky effect is essential because tiny heat-related forces can move asteroids over millions of years and alter long-term impact risk. The near-Earth asteroid population is young and continually replenished from the main belt and cometary sources, so tracking its dynamics is an ongoing need.

Data Points: Asteroid size: 45 meters - Bill Nye describes 2012 DA14 as roughly half a soccer field in diameter. Closest approach distance: 17,000 nautical miles / about 27,000 kilometers / about 17,000 miles - Multiple speakers give the flyby distance for 2012 DA14. Flyby timing: February 15, 2013 at 19:25 UT - Bruce Betts gives the closest-approach time. Apparent motion at closest approach: 1 degree per minute - Bruce Betts notes how fast DA14 would move across the sky. Orbital period change: 368 days to 317 days - The asteroid’s orbit will be measurably altered by Earth’s gravity during the flyby. Impact frequency estimate: About every 1,200 years - Bruce Betts cites the average impact interval for an object of this size. Flyby frequency estimate: About every 40 years - Bruce Betts says objects of this size pass by Earth on average every few decades. Asteroid population estimate: About 100,000 comparable objects - Bill Nye refers to the approximate number of similar-size objects out there. Tunguska reference size: 2,000 square kilometers of flattened trees - Bill Nye compares the scale of a potential impact to the Tunguska event. Main belt inventory growth: About a factor of five - Amy Mainzer says asteroid counts in the main belt have increased dramatically over 10 years. Near-Earth object residence time: A few million to a few tens of millions of years - Amy Mainzer explains near-Earth objects are relatively young compared with main-belt asteroids. OSIRIS-REx launch year: 2016 - Edward Bayshore says the sample-return mission was planned to launch in 2016. OSIRIS-REx arrival year: Late 2018 - The mission is expected to arrive at asteroid 1999 RQ36 then. Sample return year: 2023 - The returned asteroid sample is planned to come back to Earth in 2023. Sample significance: Largest extraterrestrial sample returned since Apollo - Ed Bayshore emphasizes the historic scale of the sample return. Landsat record start: 1972 - Emily notes Landsat has been orbiting Earth since 1972. Number of Landsat satellites: 8th satellite - Emily references the upcoming Landsat Data Continuity Mission. Shoemaker-Levy/Eros landing year: 2001 - Bruce Betts mentions the Near Earth Asteroid Rendezvous mission landing on Eros.

Pivotal Quotes: "it is a time for everybody to celebrate the diligence of space explorers who use telescopes from the Earth" — Bill Nye: Bill reacts to the successful discovery and tracking of 2012 DA14 and the broader asteroid-search effort. "For OSIRIS-REx, the force of sunlight pushing on the spacecraft will be comparable to the gravitational force from the asteroid" — Edward Bayshore: He explains the operational challenges of working in the extremely weak gravity environment around a small asteroid. "it's like little flippers in a pinball machine" — Amy Mainzer: She describes how gravitational resonances can move asteroids from the main belt into near-Earth space.

Implications: The episode underscores that asteroid detection, tracking, and sample-return missions are central to both planetary defense and planetary science. It also shows how public tools and outreach can turn complex data into broader engagement and preparedness.