Skip to Content
Uncategorized

Estimating the orbit of Planet X

If Planet X is out there in the icy reaches of the Solar System, we should see its affect on the orbital motion of the inner planets

“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

Workers disinfect the street outside Shijiazhuang Railway Station
Workers disinfect the street outside Shijiazhuang Railway Station

Why China is still obsessed with disinfecting everything

Most public health bodies dealing with covid have long since moved on from the idea of surface transmission. China’s didn’t—and that helps it control the narrative about the disease’s origins and danger.

crypto winter concept
crypto winter concept

Crypto is weathering a bitter storm. Some still hold on for dear life.

When a cryptocurrency’s value is theoretical, what happens if people quit believing?

individual aging affects covid outcomes concept
individual aging affects covid outcomes concept

Anti-aging drugs are being tested as a way to treat covid

Drugs that rejuvenate our immune systems and make us biologically younger could help protect us from the disease’s worst effects.

Stay connected

Illustration by Rose WongIllustration by Rose Wong

Get the latest updates from
MIT Technology Review

Discover special offers, top stories, upcoming events, and more.

Thank you for submitting your email!

Explore more newsletters

It looks like something went wrong.

We’re having trouble saving your preferences. Try refreshing this page and updating them one more time. If you continue to get this message, reach out to us at customer-service@technologyreview.com with a list of newsletters you’d like to receive.