Kordylewski cloud

From Wikipedia, the free encyclopedia

Diagram showing the positions of Lagrangian points L4 and L5, in which there are Kordylewski clouds
Diagram showing the positions of Lagrangian points L4 and L5, in which there are Kordylewski clouds

Kordylewski clouds are large concentrations of dust that may exist at the L4 and L5 Lagrangian points of the Earth-Moon system. They were first reported by Polish astronomer Kazimierz Kordylewski in the 1960s, but there is still controversy as to whether they actually exist, due to their extreme faintness. It is thought by some that they could be a transient phenomenon as the L4 and L5 points are unstable due to the perturbations of the Sun.

They were first seen visually by Kordylewski in October 1956, when he saw a glow about 2° in angular size and half as bright as the Gegenschein. He then photographed them in 1961 when they seemed to change in size and shape. In 1967 J. Wesley Simpson made observations using the Kuiper Airborne Observatory.

If they are in fact 2° angular size as seen from Earth, they could be at least 14000 km (8700 miles) across, about the size of the Earth.

  • Kazimierz Kordylewski (1961). "Photographische Untersuchungen des Librationspunktes L5 im System Erde-Mond". Acta Astronomica 11: 165-169. 
  • (1967) "Dust Cloud Moons of the Earth". Physics Today 2: 39-46. 
  • (1989) "Photographic Observations of the Clouds in the Neighbourhood of Libration Point L5 of the Earth-Moon System". Earth, Moon and Planets 47 (2): 193-215. 
  • Hypothetical Planets
  • A Search for Objects near the Earth-Moon Lagrangian Points, by Francisco Valdes and Robert A. Freitas Jr., did not find any objects at the Earth-Moon or Earth-Sun lagrange points, but this survey was not sensitive to diffuse clouds.

Advanced Search
Included Web Search Engines


Safe Search

close

Top Matching Results

Occasionally Search.com will highlight specialized results that are based on the context of your query. Examples of specialized results include specific links to news, images, or video.

Top Matching Results may highlight information from other Search.com pages, content from the CNET Network of sites, or third party content. The listings are based purely on relevance. Search.com does not receive payment for listings in this section but our partners that provide this data may get paid for listing these products.

Sponsored Links

This section contains paid listings which have been purchased by companies that want to have their sites appear for specific search terms and related content. These listings are administered, sorted and maintained by a third party and are not endorsed by Search.com.

Search Results

Search.com sends your search query to several search engines at one time and integrates the results into one list which has been sorted by relevance using Search.com's proprietary algorithm. You can customize the list of search engines included in your metasearch from the preferences.

The search engines that are used in your metasearch may allow companies to pay to have their Web sites included within the results. To view the Paid Inclusion policy for a specific search engine, please visit their Web site. Search.com does not accept payment or share revenue with any search engine partner for listings in this section.