Press Release
New Planet Found in the Outer Solar System
2 October 1992
A new planet has just been found in the outer solar system. Although the observations do not yet allow an accurate determination of its orbit, it appears that it is situated about 6,000 million km away, outside the orbit of the outermost, known planet, Pluto. No other object has ever been found this far out in the solar system.
Discovery and Follow-up Observations
The new planet, which has received the provisional designation 1992 QB1, was first seen by American astronomers David Jewitt and Janet Luu, working with the University of Hawaii 2.2-metre telescope at Mauna Kea on the Big Island of Hawaii. They noticed the faint object on August 30, 1992 and again on the two following nights, in the constellation of Pisces (The Fish), rather near the celestial equator. The image was star-like and the motion was very slow, indicating that the object might be a very distant minor planet. The brightness of 1992 QB1 was about 23, or 6,000,000 times fainter than what can be seen with the unaided eye. The colour was reddish.
An excellent extrapolation of the motion by Brian Marsden of the Minor Planet Centre of the International Astronomical Union (Cambridge, Mass., USA) permitted renewed observations of 1992 QB1 after the full-moon period in mid-September. At the ESO La Silla Observatory, astronomers Alain Smette (ESO) and Christian Vanderriest (Observatoire de Meudon, France) obtained three images with the 3.5 m New Technology Telescope on September 27 and 28. Reproductions of these images are shown on the photo accompanying this Press Release. The brightness was about the same as at the time of the first observations, one month earlier.
These images were transmitted via the permanent satellite data link to the ESO Headquarters in Garching, where astronomer Olivier Hainaut (ESO) accurately measured the positions of the slowly moving planet. With the help of the new positions, Brian Marsden was able to confirm the great distance of 1992 QBl, but due to its extremely slow motion, it must be observed during another couple of months, before a more accurate orbit can be computed.
The Nature of 1992 QB1
On the assumption that it moves in a circular orbit around the Sun, Brian Marsden estimates its distance from the Sun to be about 41 Astronomical Units (AU), or more than 6,000 million km, i.e., just outside the orbit of the most distant known planet Pluto. This corresponds to a period of revolution around the Sun of 262 years. Pluto was discovered in 1930 by Clyde Tombaugh at the Lowell Observatory in Arizona, USA, and no other object that orbit the Sun has ever been found at such a large distance .
From its brightness, the diameter of 1992 QBl is estimated at 200 km. It therefore belongs to the class of Minor Planets. However, almost all Minor Planets move inside the orbit of the giant planet Jupiter (5.3 AU, or only 800 million km from the Sun), and only two are known which are at the distance of Saturn.
It cannot at this moment be entirely excluded that the new object is an extremely distant comet that has undergone an outburst, similar to that of Comet Halley in early 1991 which was extensively observed at ESO. However, the constant brightness during one month does not support this speculation and astronomers believe that it is a planet with a solid surface, probably covered with a reddish residue of organic-rich materials.
1992 QBl is an extremely interesting object and will be intensively observed with large telescopes during the coming months, at ESO as well as at a few other observatories.
Contacts
Richard West
ESO EPR Dept
Garching, Germany
Email: information@eso.org
About the Release
| Release No.: | eso9214 |
| Legacy ID: | PR 08/92 |
| Name: | 1992 QB1 |
| Type: | Solar System : Interplanetary Body |
| Facility: | New Technology Telescope |
Images
Our use of Cookies
We use cookies that are essential for accessing our websites and using our services. We also use cookies to analyse, measure and improve our websites’ performance, to enable content sharing via social media and to display media content hosted on third-party platforms.
ESO Cookies Policy
The European Organisation for Astronomical Research in the Southern Hemisphere (ESO) is the pre-eminent intergovernmental science and technology organisation in astronomy. It carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities for astronomy.
This Cookies Policy is intended to provide clarity by outlining the cookies used on the ESO public websites, their functions, the options you have for controlling them, and the ways you can contact us for additional details.
What are cookies?
Cookies are small pieces of data stored on your device by websites you visit. They serve various purposes, such as remembering login credentials and preferences and enhance your browsing experience.
Categories of cookies we use
Essential cookies (always active): These cookies are strictly necessary for the proper functioning of our website. Without these cookies, the website cannot operate correctly, and certain services, such as logging in or accessing secure areas, may not be available; because they are essential for the website’s operation, they cannot be disabled.
Functional Cookies: These cookies enhance your browsing experience by enabling additional features and personalization, such as remembering your preferences and settings. While not strictly necessary for the website to function, they improve usability and convenience; these cookies are only placed if you provide your consent.
Analytics cookies: These cookies collect information about how visitors interact with our website, such as which pages are visited most often and how users navigate the site. This data helps us improve website performance, optimize content, and enhance the user experience; these cookies are only placed if you provide your consent. We use the following analytics cookies.
Matomo Cookies:
This website uses Matomo (formerly Piwik), an open source software which enables the statistical analysis of website visits. Matomo uses cookies (text files) which are saved on your computer and which allow us to analyze how you use our website. The website user information generated by the cookies will only be saved on the servers of our IT Department. We use this information to analyze www.eso.org visits and to prepare reports on website activities. These data will not be disclosed to third parties.
On behalf of ESO, Matomo will use this information for the purpose of evaluating your use of the website, compiling reports on website activity and providing other services relating to website activity and internet usage.
Matomo cookies settings:
Additional Third-party cookies on ESO websites: some of our pages display content from external providers, e.g. YouTube.
Such third-party services are outside of ESO control and may, at any time, change their terms of service, use of cookies, etc.
YouTube: Some videos on the ESO website are embedded from ESO’s official YouTube channel. We have enabled YouTube’s privacy-enhanced mode, meaning that no cookies are set unless the user actively clicks on the video to play it. Additionally, in this mode, YouTube does not store any personally identifiable cookie data for embedded video playbacks. For more details, please refer to YouTube’s embedding videos information page.
Cookies can also be classified based on the following elements.
Regarding the domain, there are:
- First-party cookies, set by the website you are currently visiting. They are stored by the same domain that you are browsing and are used to enhance your experience on that site;
- Third-party cookies, set by a domain other than the one you are currently visiting.
As for their duration, cookies can be:
- Browser-session cookies, which are deleted when the user closes the browser;
- Stored cookies, which stay on the user's device for a predetermined period of time.
How to manage cookies
Cookie settings: You can modify your cookie choices for the ESO webpages at any time by clicking on the link Cookie settings at the bottom of any page.
In your browser: If you wish to delete cookies or instruct your browser to delete or block cookies by default, please visit the help pages of your browser:
Please be aware that if you delete or decline cookies, certain functionalities of our website may be not be available and your browsing experience may be affected.
You can set most browsers to prevent any cookies being placed on your device, but you may then have to manually adjust some preferences every time you visit a site/page. And some services and functionalities may not work properly at all (e.g. profile logging-in, shop check out).
Updates to the ESO Cookies Policy
The ESO Cookies Policy may be subject to future updates, which will be made available on this page.
Additional information
For any queries related to cookies, please contact: pdprATesoDOTorg.
As ESO public webpages are managed by our Department of Communication, your questions will be dealt with the support of the said Department.