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In this article the author offers information on the solar system's changing landscape as it appears in planet Earth's sky during the month of September 2011. Topics include an overview of planets that are easily observable in September, such as Saturn, Venus, and Uranus, and the best times to view the planets Mars, Mercury, and Jupiter's satellite Ganymede as it enters Jupiter's shadow. INSETS: Witness the subtle glow of a "false dawn";Catch Luna's brightest feature;Garradd guarantees to put on a fall show;Vesta puts on the brakes in Capricornus

The Voyager spacecrafts which traveled past Jupiter in 1979 revealed the cratered countenance of Callisto, the valleys and ridges of Ganymede, the cracked face of Europa, and the spewing volcanoes of Io. But it would take a spacecraft named for Italian scientist Galileo, who discovered the moons in 1610, to reveal the true complexity of these worlds and to begin to divulge their interior secrets. Viewed from afar, Callisto appears heavily cratered, with few signs of internal activity. Up close, Callisto's dark surface appears as a smooth fog that cloaks the moon's contours. The process of sublimation, which occurs when solid material turns directly into gas, best explains the origin of this rubbly surface, A mixture of ice and rock delivered by colliding comets and ice-rich planetesimals can sublimate slowly over time, leaving dusty debris behind. Of the Galilean satellites, Callisto's ancient, cratered surface should hold the most pristine and primitive material, the stuff from which the moons were built. The gravity studies suggest that Callisto is a mix of rock and ice deep into its interior and that its constituents are only partially segregated. This implies that the moon's innards never melted throughout, somehow staying relatively cool as Callisto accreted in the ancient jovian nebula. The magnetic field around Callisto provides another peek beneath the moon's surface and points to an astonishing conclusion: Callisto probably hides a subsurface ocean today. Although Callisto does not generate its own magnetic field, Galileo found that the powerful magnetic field of Jupiter induces one in Callisto. Although the decay of radioactive elements left over from Callisto's formation does not generate enough heat to melt pure ice today, salts or just a bit of ammonia could play the role of antifreeze. As pressure increases within Callisto, common ice like that found in our freezers is transformed into more compact forms.

Presents observations about Jupiter's satellite Ganymede. Existence of grooves less than a kilometer wide that rake across Uruk Sulcus; Parallel fractures that cleave the large, white-outlined crater; Mixture of terrain in Uruk Sulcus.

A chart is presented is presented which shows the size and diameter of the largest moons of each planet as compared to the moons of planet Mercury and Pluto including Ganymede, Triton, and Titania.

The article describes the various moons that orbit around the planet Jupiter and how they are effected and influenced by the planet itself. The author explains how impacts of these moons are responsible for the dust rings that also orbit Jupiter. A description of the moon Ganymede is also provided, explaining that it is larger than Mercury and produces its own magnetic field.

The article discusses a study published online in the March 12, 2015 issue of the periodical "Geophysical Research: Space Physics" which showed that astronomers have delivered the first observational evidence that Jupiter's moon Ganymede has a vast underground ocean, with its own magnetic field.

The article discusses the completion of the first global map of planet Jupiter’s moon Ganymede. The U.S. National Aeronautics & Space Administration (NASA) used images from various spacecraft including Voyager 1 and 2. A team of astronomers used the data to create a detailed map of the geological features of Ganymede. Astronomers hope to learn about Ganymede’s formation and history from the map.

The article discusses the planet Jupiter and its four bright Galilean moons including Europa, Io, and Ganymede. Topics include an overview of the alignments of Europa and Ganymede causing them to cast their shadow on one another and when the occults can be viewed in the U.S. and Europe.

The article announces a joint expedition between the U.S. National Aeronautics and Space Administration (NASA) and the European Space Agency (ESA) to explore Jupiter and its largest moons. The expedition is expected to launch in 2020. The scientific attractiveness of studying the moons Europa and Ganymede is noted, mentioning the possibility that microbial life could exist on Europa.

The article focuses on Jupiter, which appears best for astronomy observers at opposition on June 5, 2007. Saturn has a 12-year orbit around the Sun, and each opposition, which happens every 13 months, occurs one constellation farther east than the previous year's. Jupiter's four major moons--Io, Europa, Ganymede, and Callisto--can be seen through a telescope.

The Galileo mission concluded on September 21, 2003 as the spacecraft made a fiery final plunge into the atmosphere of Jupiter. Galileo, launched in 1989, had been orbiting Jupiter since December 1995. It dropped a probe into Jupiter and made a total of 35 orbits around the giant planet. Galileo's many discoveries include high-temperature volcanism on Io, a suspected ocean under Europa's icy crust, and a magnetic field at Ganymede.

Jupiter and its moon Ganymede have teamed up to help astronomers obtain a rare view of another jovian moon, Io. University of California at Berkeley astronomer Imke de Pater and her colleagues took infrared images used to measure the temperatures of lava flows at dozens of Io's volcanoes. Io is the most geologically active object in the solar system. Interior heat, generated by tidal forces "kneading" the satellite, drives flows of molten magma to the surface. The resulting lava flows glow in the infrared. This wavelength of light does not pass easily through Earth's atmosphere and can be observed only by satellites or high-altitude telescopes like the 10-meter Keck II, on Mauna Kea, Hawaii, that de Pater and colleagues utilized.

Reports on the discovery of subsurface oceans on the moons of Jupiter through the National Aeronautics and Space Administration's Galileo spacecraft. Details on the observations of a magnetometer team on the magnetic fields of the moons; Discovery of hydrated salts on the surface of the moon Ganymede; Implications of the discoveries to the search for extraterrestrial life in the solar system.

Speculates the existence of salt water in a subterranean layer of Jupiter's Ganymede, the largest moon in our solar system. Findings of the Galileo scientists on Jupiter's moon.

Presents the photographs of Jupiter's tectonically active moon Ganymede which shows a jumble of terrains of various ages. Possible existence of water-ice frost in the northern latitudes of Ganymede.

Reports on findings of the spacecraft Galileo regarding Jupiter's moon, Ganymede. Photo survey of moon; Revelations from the probe on Jupiter's atmosphere.

Reports that Jupiter's largest satellite, Ganymede, seems to be making ozone in the ices at its surface. Percentage of ozone; How the ozone is formed.