Dr. Müller adjusted his glasses.
“We know now that this was no anomaly in sensor reading. The Voyager spacecraft are, in fact, working perfectly.” He coughed. “I know you are all familiar with the accepted solutions, but today I am going to explain how we have all been wrong.” He pulled off his glasses, rubbed his eyes with the back of his hand before looking around the room. “How we have all been terribly wrong.”
A murmur rose from the crowd in the room.
“What we now know is that a massive and previously unknown object is on its way toward us at extremely high speed.”
“Wouldn’t we have detected this in our radial velocity searches?” asked a voice from the left side of the room.
Ben squinted. Who was that? A young man wearing a knitted cap pulled halfway back on his head, a scarf carelessly hung around his neck, silver earrings dangling—he looked too stylish to be an astrophysicist.
It took Ben a second to realize he was looking at Ufuk Erdogmus. He’d only ever seen him on TV before. After earning a fortune of hundreds of millions on Internet start-ups in his twenties, he turned that into tens of billions by founding the world’s first private space-launch company and an electric car company, and by developing human life-extension technology. Not bad for a forty-year-old.
Erdogmus was best known, however, for launching Mars First, a one-way, privately funded mission to send humans to Mars. The Apollo program took less than a decade from John Kennedy’s famous speech to landing men on the moon, and five years ago Erdogmus had boasted that he could do better. And he made good on his promise—just three years after he announced it, the Mars First mission was launched two months ago. Eight humans, in hibernation sleep, were now aboard a one-way, three-year, long-trajectory flight path to Mars. The one-way part of the mission description was controversial, to say the least, but hundreds of people had volunteered for a chance to be the first to walk on Mars.
Ben had thought the project was madness; a suicide mission dreamed up as a promotional stunt for Erdogmus’s empire. But on reflection, he realized that real explorers of the past usually were on what amounted to suicide missions. We just didn’t have the risk appetite anymore—maybe Ufuk was right in what he was doing.
All that aside, what was Ufuk Erdogmus doing in this room right now? Then Ben remembered reading that he was doing the keynote speech for the IAU meeting. And regardless, Ufuk’s question was exactly the right question to ask; the reason why the exoplanet people had been called into this meeting.
The search for planets around other stars used several techniques, one of them called “radial velocity,” which detected the “wobble” in a distant star based on the change of its speed toward or away from us. Radial velocity measurements were extremely precise—Ben could record differences in speed down to meters per second, about how fast someone walked, when measuring a star trillions of kilometers away moving at hundreds of kilometers a second. And it could certainly measure whether the Earth, and the solar system with it, was falling toward some nearby object.
Dr. Müller turned and smiled. “The answer, Mr. Erdogmus, is that we have measured the presence of this object in our radial velocity searches. We just didn’t know it. This independent verification is why I have called all of you here today. I’ve gone through NASA’s own data and analyzed our ‘fudge factors’—and time after time, the signal is there, staring at us in the face. An acceleration factor that we had previously attributed to dark matter in the nearby spiral arm of the Milky Way.”
Fear jangled again in Ben’s fingertips. He was hearing the full explanation for the first time, and he hadn’t been entirely convinced the night before.
When measuring radial velocity to search for an exoplanet, only the wobble was of interest, not the constant effects. You subtracted the Earth’s rotation, the movement of an orbiting observatory, the motion of the Earth around the sun, the motion of the Sun around the galactic core—everything pushed and pulled apart by gravity—and after that, even allowed for the heating or cooling of the device itself, down to the tiniest of imperfections in the system. Each observation team had a long list of “fudge factors” they used for their own systems.
The question Dr. Müller now posed: was there an overlooked factor they all shared?
If so, what exactly was it?
4
CHIANTI, ITALY
JESS STARED AT HER mother.
“Jail?” Celeste winced. “Again?” Her shoulders dropped but hitched back up quickly, her lips pressing together as she took a long look at her daughter. “Is that why you rushed me all the way out here?”