Pioneer 10’s peculiar path through space poses a compelling mystery for physicists
On March 2, 1972, a balmy Thursday on Florida’s humid Cape Canaveral peninsula, a NASA Atlas-Centaur rocket blasted off with a 570-pound payload called Pioneer 10. Pioneer was a space probe designed to cross the belt of asteroids and make a “flight”. -by” from Jupiter and the outer gas giants to study them. Over the next ten years, Pioneer sent back amazing reports from the far reaches of the solar system, carrying out its mission with flying colors.
Then, instead of going silent as expected, Pioneer continued to send signals to Earth. His little nuclear generator kept producing the 70 watts of power needed to maintain a radio link with the Jet Propulsion Laboratory in Pasadena, California, and this went on for decades longer than anyone thought possible. Communication was maintained daily until January 23, 2003, more than thirty years after the start of the mission. By then, the probe was twice as far from the sun as Neptune and Pluto, and Pioneer had become the first man-made object to leave the clutches of the sun’s gravity forever.
The Pioneer story would have been a significant chapter in the history of science if it had ended there, but it didn’t. Experimental physics is full of examples of scientific projects designed to study one phenomenon but revealing unexpected truths about something else entirely, and the really interesting piece of Pioneer 10 history is one of them. Although he had carried out his robotic exploration of Jupiter and Saturn with skill and perseverance far beyond the call of duty (if that language can be applied to a robot), when he was passing the outer limits of the planetary system, it was clear to NASA that it was hundreds of thousands of miles from where the tracking software said it should be. How was that possible?
The way objects move in space, whether they are Jupiter-sized planets or small spacecraft like Pioneer, is governed by well-known laws of physics that provide precise answers about location that can be measured in centimeters, even in the sun scale. system. For Pioneer, being millions of miles off course just wasn’t possible. No matter how it was approached, the problem just wouldn’t go away and it soon became clear that something really strange was going on. NASA scientists gave this Pioneer quirk a name; They called it “The Anomaly”.
“The Pioneer Detectives: Did a Distant Spaceship Prove Einstein and Newton Wrong?” A recently published “Single Kindle” by Konstantin Kakaes, a talented journalist and writer who studied physics as an undergraduate at Harvard, explores the tantalizing clues scientists uncovered in trying to explain Pioneer’s drift. The more they dug, the less they seemed to understand. Immersed in the 30-year-old space probe’s daily tracking records, initial and perhaps game-changing questions began to surface: Was the spacecraft’s errant course evidence of some new and unknown wrinkle in the fundamental laws of physics?
A spacecraft slightly off course might seem like an unlikely subject for deep speculations about the fundamental nature of the universe, but the obvious solutions for Pioneer’s flight deflection weren’t forthcoming. However, this was a matter of “black letter” physics, and errors of this kind and of this magnitude simply cannot occur.
What could be the cause of “The Anomaly”? NASA detectives didn’t seem to agree, though the list of possible culprits was long and terrifying: Dark matter? Tensor-vector-scalar gravity? Collisions with gravitons? A fundamental error in Einstein’s equations?
The only thing clear about the questions raised by Pioneer and “The Anomaly” was that potentially groundbreaking discoveries lay ahead for those brave and smart enough to tackle them successfully. This is a territory that young scientists call “new physics”, a land without maps where new Nobel laureates are also sometimes found.
Writing in crisp, clear prose free of technical language, science writer and former Mexico City bureau chief of “The Economist” Konstantin Kakaes gives us a chilling scientific detective story, tracing the thought processes and groundwork of those committed to unraveling this high-stakes riddle of science. Kakaes is based on extensive interviews and archival research, following the story from the initial discovery of “The Anomaly” through decades of tireless research, to its final conclusion. “The Pioneer Detectives” is a riveting and definitive account of not only the pioneer anomaly, but also how scientific knowledge is made and unmade, with scientists sometimes risking their reputations and livelihoods in search of cosmic truths.
This was a great read that kept me up very late at night. Highly recommended.