Estimating the orbit of Planet X
“Does the Solar System contain undiscovered massive planets or a distant stellar companion of the Sun?” asks Lorenzo Iorio at the Istituto Nazionale di Fisica Nucleare in Pisa, Italy.
If it does, then the orbital period of such a body would be so long that any gravitational influence on the known planets can be thought of as a constant, tiny perturbation.
Iorio has looked at a the perihelion precessions of Venus, Earth and Mars in the last century and asked whether there is any indication of such a force in action.
Apparently not, he says, but that doesn’t rule out its presence. Instead, it has allowed Iorio to place limits on how far away such a planet might be.
His conclusion is that if Planet X is out there and about the size of Earth, it must more than 130 AU away. If it is the size of Jupiter, it cannot be closer than 886 AU and if it were a brown dwarf with a mass around 80 times that of Jupiter, it would have to be more than 3800 AU away.
Let’s get looking!
Ref: arxiv.org/abs/0904.1562: Constraints on Planet X and Nemesis from Solar System’s Inner Dynamics
Keep Reading
Most Popular
Geoffrey Hinton tells us why he’s now scared of the tech he helped build
“I have suddenly switched my views on whether these things are going to be more intelligent than us.”
ChatGPT is going to change education, not destroy it
The narrative around cheating students doesn’t tell the whole story. Meet the teachers who think generative AI could actually make learning better.
Meet the people who use Notion to plan their whole lives
The workplace tool’s appeal extends far beyond organizing work projects. Many users find it’s just as useful for managing their free time.
Learning to code isn’t enough
Historically, learn-to-code efforts have provided opportunities for the few, but new efforts are aiming to be inclusive.
Stay connected
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.