Backyard Worlds: Planet 9

Some astronomers think there may be a large planet at the fringes of our solar system - a world they call Planet Nine. 

Join the hunt for new planets and planet-like objects called "brown dwarfs" near the Sun! This long-running project has discovered more than 3800 new brown dwarfs and published dozens of scientific papers.

Go to Project Website


18 and up







What you'll do

  • Examine images of the sky taken by NASA's WISE mission, and search them for moving objects.
  • Report your findings by clicking on them or---for a faster response—use the Think-You've-Got-One form (read about how that works here).  
  • Connect with other scientists and volunteers.
  • More than 40 volunteers have become co-authors of published scientific papers through this project!


  • Time to get started: ~15 Minutes to complete online training.
  • Equipment: Internet connected mobile device or computer
  • Knowledge: None. In-project tutorial provided.

Get started!

  1. Visit the project website
  2. Click “Get Started” and complete the Tutorial to learn the basics.  
  3. Find Worlds: Examine “flipbooks” of images to distinguish real moving objects in space from ghosts and other artifacts.

Learn More

Join the Zooniverse Talk to learn from peers and scientists. 

Get to know the Backyard Worlds: Planet 9 Team and some of the people who have contributed.

We see a planet with a drawn-on simple smily face and stick-arms holding an old-fashioned spyglass up to its dot of a right eye. The planet's surface has blue and green patches that make it look like Earth.
Image shows the relative sizes of Earth (very small in bottom right corner), Jupiter (with a diameter is 11.5 times larger than Earth with visible stripes), a Brown dwarf (slightly larger than Jupiter and bright red with stripes), and a low-mass star (roughly twice the size of the Brown Dwarf). A fifth celestial body, far larger than the Low Mass Star, is partially visible in the upper left of the image.
Illustration of the relative sizes of low mass stars, brown dwarfs, Jupiter (a gas giant), and Earth.
Two star-dotted images of space sit side-by-side, one labeled “January 23, 1930” and the second “January 29, 1930.”. A small white arrow is visible in each image, in a different place, pointing out a small light spot - Pluto - that has moved from one image to other.
There’s still no substitute for the human eye when it comes to recognizing subtle motions in astronomical images. This pair of images - one from Jan 23, 1930 and one from Jan 29 1930 - show the movement of Pluto.

Get to know the people of Backyard Worlds: Planet 9!

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Vinod Thakur

Citizen Scientist

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Peter Ansorge

Citizen Scientist/ Business Consultant

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Jackie Faherty

Astrophysicist/ Scientist at American Museum of Natural History

Marc Kuchner

Astrophysicist/ Citizen Science Officer

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Hugo Durantini Luca

Citizen Scientist / Astronomy Student

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Frank Kiwy

Citizen Scientist / Senior Software Developer

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Jörg Schumann

Citizen Scientist / Accountant

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Michaela Allen

Citizen Scientist/ Graduate Student

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Melina Thévenot

Citizen Scientist

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Dan Caseldon

Citizen Scientist / Security Engineer

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Les Hamlet

Citizen Scientist/ Materials Testing

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Tamara Stajić

Citizen Scientist/ Machine Learning Engineer

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Rosa Castro

Citizen Scientist / Retired Mental Health Therapist

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Guillaume Colin

Citizen Scientist / Pulmonologist