Europa ("yoo ROH puh") is the sixth of Jupiter 's known satellites and the fourth largest; it is the second of the Galilean moons. ... Discovered by Galileo and Marius in 1610. ... But Europa's surface is not at all like anything in the inner solar system. ... The images of Europa's surface strongly resemble images of sea ice on Earth. It is possible that beneath Europa's surface ice there is a layer of liquid water , perhaps as much as 50 km deep, kept liquid by tidally generated heat. ...

Supernova 2009js in NGC 918 . This page is devoted to information on Supernova 2009js in NGC 918 . Basic information on this SN, including the last reported brightness, on this Supernova can be found on the main page . Information on the original web pages for many of these images can be found on the updates and links web pages. Discovered independently by Lick Observatory Supernova Search (USA) and Koichi Itagaki (Japan). ... 2009/10/11.44 . 17.2 . ... Joseph Brimacombe . ...

... February 3, 1998 . A Magellanic Mural . ... Explanation: Two galaxies stand out to casual observers in Earth's Southern Hemisphere : the Large Magellanic Cloud (LMC) and the Small Magellanic Cloud (SMC). ... Recent observations of the LMC (on the left) have determined that it is on a nearly circular orbit around our Galaxy, and have even helped in the determination of the composition of dark matter in our Galaxy . ... About APOD > . ...

... We have compiled the Catalogue of extragalactic supernovae using the GCVS card catalogue. ... Doubtful (?), or rejected (-) SN 8 A1 --- RemFlag [*] The '*' indicates a remark in sn_rem.dat 10- 19 A10 --- Gal Parent galaxy designation 21- 22 I2 h RAh Right Ascension 1950 of Parent galaxy 23- 24 I2 min RAm Right Ascension 1950 (minutes) 25- 28 F4.1 s RAs Right Ascension 1950 (seconds) 29 A1 --- DE- Declination 1950 (sign) 30- 31 I2 deg DEd Declination 1950 of Parent ...

. Moscow Astronomical Plate Archives: Contents, Digitization, Current and Possible Applications. Light Curves of New Variable Stars Discovered on Scans of Moscow Collection Plates, Field 66 Oph (MDV). MDV catalog - CDS access. Moscow plate collection (Sternberg Astronomical Institute), S.Yu. Shugarov's interactive page. Send questions and comments to N. Samus and S. Antipin .

... Here is a brief outline of the current theory of the events in the early history of the solar system: . A cloud of interstellar gas and/or dust (the "solar nebula") is disturbed and collapses under its own gravity. ... The gas cools off enough for the metal, rock and (far enough from the forming star) ice to condense out into tiny particles. (i.e. some of the gas turns back into dust). ... Once the larger of these particles get big enough to have a nontrivial gravity, their growth accelerates. ...