The atmosphere of the giant planet Jupiter presents cloud systems even to the Earth-bound observer equipped with a smaller telescope. These clouds show a dynamic pattern of movements which largely depends on planetographic latitude, that is for example, on whether they are situated near Jupiter's equator or near one of its poles. The aim of JUPOS is to collect precise positions of jovian cloud features, to analyse them in drift charts, and to examine if and how their movements change in time. JUPOS is an amateur astronomical project.

WinJUPOS measurement screen

Example of a WinJUPOS measurement screen (image by Tomio Akutsu)

Most important software tool of the project is WinJUPOS written by Grischa Hahn. It is specially designed for amateur astronomers to record and analyse positions of features on Jupiter (and other planets), and to display them in suitable time-longitude or other coordinate systems. With its help you are able to process visual observations (Central Meridian transit timings, micrometer measurements) but also to measure electronic images (scanned photos, CCD or webcam images). Positions are written to a special JUPOS database, and can be queried, filtered and displayed graphically.

My thanks are going to planetary groups and individual observers of many countries who sent and forwarded many observations, or have measured images. Many thanks also to Holger Haug, Augsburg and Christian Kowalec, Berlin for providing the complete data set of the 1979 International Jupiter Voyager Telescope Observations Programme (IJVTOP).


To visit the main page of the JUPOS project, go to https://jupos.org or https://jupos.hier-im-netz.de