2007 OR10

Help astronomers name the largest unnamed world in our Solar System.

Who are we?

We are 3 astronomers: Meg, Mike, and David. Over ten years ago, we discovered (225088) 2007 OR10 at Palomar Observatory near San Diego, California. We're asking for your help in order to pick the best fitting naming suggestion for 2007 OR10 to submit to the International Astronomical Union (IAU)

Meg Schwamb

Gemini Observatory, Hawai'i

Meg is a planetary scientist and astronomer. She currently is an assistant scientist at Gemini Observatory based in Hilo, Hawai'i. Her research focuses on the small resevoirs in the outer Solar System, Mars, and exoplanets. She studies how planets and building blocks form and evolve, applying ground-based surveys to probe our Solar System’s small body reservoirs and citizen science to mine large datasets for Solar System science. Meg is currently involved in the Planet Four citizen projects ( Planet Four, Planet Four: Terrains , Planet Four: Ridges), and Comet Hunters citizen science project. As a graduate student at Caltech, Meg helped run the Palomar Distant Solar System Survey which discovered 2007 OR10. She has also helped discover and characterize PH1-b: the first exoplanet found in a four star system.

Mike Brown

Caltech, California

Mike Brown is the Richard and Barbara Rosenberg Professor of Planetary Astronomy at the Caltech. and has been on the faculty there since 1996. He specializes in the discovery and study of bodies at the edge of the Solar System. Among his numerous scientific accomplishments, he is best known for his discovery of Eris, the most massive object found in the solar system in 150 years, and the object which led to the debate and eventual demotion of Pluto from a real planet to a dwarf planet. He is also one of the first proponents of Planet 9, a proposed Neptune-sized body lurking in the outer Solar System beyond Neptune. Mike was the principal investigator of the Palomar Distant Solar System Survey which discovered 2007 OR10. Mike is also author of "How I Killed Pluto and Why It Had It Coming", an award winning best selling memoir of the discoveries leading to the demotion of Pluto.

David Rabinowitz

Yale University, Connecticut

David is a research scientist at Yale University’s Center of Astronomy and Astrophysics and Physics Department. He is the co-discover of Eris, Haumea, Makemake, and other dwarf planets in the outer Solar System. Since 2003, David has been the principal specialist for the QUEST camera. David was a collaborator on the Palomar Distant Solar System Survey which utilized the QUEST camera. David has also led projects to survey the solar phase curves and rotation states of the largest KBOs and other icy bodies in the solar system and has been a co-investigator in surveys for nearby bright supernovae and studies of Active Galactic Nuclei (AGN) variability.

What is 2007 OR10?

(225088) 2007 OR10 is a minor planet orbiting the Sun beyond Neptune.
Use the tabs below to discover what we know.

  • Orbit
  • Discovery
  • Composition
  • Size
  • Satellite
  • Rotation

Proposed names

The naming suggestions below have been pre-selected to meet the requirements of the International Astronomical Union (IAU). Because naming the largest unnamed world in our Solar System is a big decision, we'd like you to help us!



Gonggong is a Chinese water god with red hair and a serpent-like tail. He is known for creating chaos, causing flooding, and tilting the Earth. References: [1], [2] , [3]

Read more on wikipedia



A European winter goddess of fertility, rebirth, and women. Holle makes snow by shaking out her bed. She is a patroness of household crafts especially spinning. She is linked to the Yuletide (winter solstice) season associated with mistletoe and holly, evergreen plants bearing red berries. References: [1], [2], [3], [4], [5]

Read more on wikipedia


English Norse

Part of the Æsir, Vili is a Nordic deity. Vili, together with his brothers Odin and Vé, defeated frost giant Ymir and used Ymir's body to create the universe. Ymir's flesh and bones were forged into the Earth, with Ymir's blood becoming the rivers and oceans. References: [1], [2], [3], [4].

Read more on wikipedia


Use the form below to cast your vote!

The option that gets the most votes will be submitted to the Minor Planet Center (MPC) and the International Astronomical Union (IAU) as our formal suggestion for (225088) 2007 OR10's name. Learn more about the proposed names.

Cast your vote by 11:59 pm PDT on May 10,2019

Voting is now closed. More soon as we tally the votes


Why do you want to name (225088) 2007 OR10 now?

We know, it's been a long wait! We've always wanted to have some kind of public involvement in naming 2007 OR10, but we also wanted to know more about the object to give it a name that fits. We've also been busy with research, work, and life (Meg has moved continents multiple times during this period). Thanks to Geert Barentsen who helped create this site for us.

How long do I have to vote?

Voting opens on April 9, 2019 at 06:00 AM PDT. Voting ends on May 10, 2019 at 11:59 PM PDT.

When will the results be announced?

Voting lasts for three week. After that we'll quickly announce the results on this site and then formally submit the naming suggestion for the International Astronomical Union (IAU) to consider. Check back soon for updates.

Will this be the official name?

Hopefully. When a planetesimal in the Solar System has a secure orbit, the Minor Planet Center invites suggestions from the discovers for a period up to 10 years. The Minor Planet Center passes the suggested name and justification from the discoverers to the International Astronomical Union's (IAU) Committee for Small-Body Nomenclature which makes the final decision. More details can be found here.

So we're just suggesting a name to be considered?

Yes. It is the International Astronomical Union's (IAU) Committee for Small-Body Nomenclature which makes the final decision. More details can be found here. In most past cases, the name suggested by the discoverers as long as it fits the naming guidelines has been taken as the formal name for the Solar System body, but the IAU Committee for Small-Body Nomenclature has the final say to ultimately accept or reject the naming suggestion. So, we think there's a good chance that the naming suggestion with the most votes will become the official name for 2007 OR10. If the top choice is not accepted, we will submit the second most popular choice to the IAU for consideration.

How did you pick these names?

We tried to select deities where there were links to color red and also where there was a theme of inside turning outside or with water ice/snow to connect to the suspected past cryovolcanism coating 2007 OR10 with water ice. Also, we looked for naming suggestions that have connections to other mythological creatures and deities that could be used as naming options for 2007 OR10's moon.

How long does the 2007 OR10 discovery team have to submit a naming suggestion?

Discovers have a 10 year period from when a minor planet is numbered, has an orbit that is deemed secure by the Minor Planet Center (MPC) and given a permanent number on top of its original desgination, where a name they suggest will have a stronger preference when considered by the IAU. (225088) 2007 OR10 was numbered by the MPC in November 2009. So the discovery team should submit a naming suggestion for 2007 OR10 is November 2019.

Can I see 2007 OR10 in the night sky by eye?

Unfortunately, no. We can see about visual magnitude ~8 stars by eye in very dark skies, and the brightness of of 2007 OR10 is about 21st-22nd magnitude.

When was 2007 OR10 discovered?

July 17, 2007, UT in the Palomar Distant Solar System Survey. Pre-recovery observations for 2007 OR10 have been reported to the Minor Planet Center (MPC). Observations of 2007 OR10 from as early as 1985 have been found.

What does (225088) 2007 OR10 stand for?

That's the designation that the Minor Planet Center (MPC), which keeps track of discoveries in our Solar System, gave for this Kuiper belt object. You can think of it like the license plate numbers for motor vehicles. All minor planets including Pluto and Eris have an identifier like this.

What's the Minor Planet Center?

The Minor Planet Center (MPC) is responsible for keeping track of all the discoveries and orbits for minor bodies in the Solar System. You can learn more about their mission at

How did you come up with the proposed names?

Objects in the Kuiper belt in similar orbits to 2007 OR10 must be given names associated with mythological figures associated with creation. More details on the suggested naming requirements put forth by the International Astronomical Union (IAU) can be found here and here. We tried to find mythologies from across the world that fit the IAU naming criteria and whose origin and characteristics related in some way to the properties we know of for 2007 OR10. We tried to keep in mind that there's a moon that will also need a name. The discovers of 2007 OR10's satellite will have the right to submit a name for the moon, so we looked for naming options for 2007 OR10 where there would also be some suitable related naming options for the moon.

Where did the audio pronunciations come from?

The audio pronunciations of each candidate name are thanks to Øyvind Guldbrandsen (Vili), Ralf Edmund Stranzenbach (Holle), and Quanzhi Ye 叶泉志 (Gonggong), with help from Emily Lakdawalla.

I've got a cool name to suggest. Who should I get in touch with?

That's great, but we're going to pick the naming suggestion with the most votes from our list of three.

Can we suggest names for (225088) 2007 OR10's moon?

Sorry, not for this vote. We didn't find the moon, so that's up to discovers of S/(225088) 1 to decide how they want to go about selecting a name for their discovery.

Can I vote more than once?

Yes, you can vote for your favorite naming suggestion more than once, but we ask that you only vote twice per day so that all participants' voices have a fair chance of being heard.

Does the International Astronomical Union (IAU) know you're doing this?

The IAU has outlined a process for obtaining IAU support/approval for public naming campaigns. We have gone through this process.

Who designed the cool background image for the website?

That would be Alex Parker. Check out his other science visualizations and artwork here.