On Jupiter s moons

Carlson R. W. (1999) A tenuous carbon dioxide atmosphere on Jupiter s moon Callisto. Science 283, 820-821. 

The reflectance spectra of solidified liquid sulfur previously equihbrated at temperatures of between 120 and 440 °C have been measured at 25 °C and color pictures of these solidified melts were published [112]. These data are used to explain the yellow, orange and red colors of the sulfur flows on Jupiter s moon lo on which a number of very active sulfur volcanoes have been discovered [113]. These volcanoes are powered by SO2 gas which forces the liquid sulfur from its underground deposits to the surface. 

Infrared spectra from NASA s Galileo mission show distinct absorptions on Jupiter s moon Europa that have been attributed to one or more sulfuric acid hydrates. Sulfuric acid in solution with water causes significant freezing-point depression of water s melting point, down to 210 K, and this would make more likely the existence of liquid solutions beneath Europa s icy crust.The interpretation of the spectra is somewhat controversial. Some planetary scientists prefer to assign the spectral features to the sulfate ion, perhaps as part of one or more minerals on Europa s surface. 

Jupiter s moon lo on which a number of very active sulfur volcanoes have been discovered [64]. These volcanoes are powered by SO2 gas which forces the hquid sulfur from its underground deposits to the surface. 

Jupiter s moon Europa has only been the subject of intense scientific investigation in recent years it is considered to be a member of that small group of heavenly bodies which could perhaps accommodate life (or a precursor of life). About 20 years ago, the Voyager passes afforded sensational pictures of Europa. These showed a network of linear bands, of differing breadths, on a very bright surface. The mean density was calculated as 3,018 35 kg/m3, and the surface temperature measured was 90-95 K. Circumstantial evidence points to either a surface consisting of water ice, or the presence of liquid water or warm ice under the surface. Three models were proposed (Oro et al., 1992) ... 

Europa, one of Jupiter s moons, has an icy surface with hints of vast oceans of liquid water beneath. Is there life on Europa If so, perhaps some Europan astronomer viewing Earth would be asking a similar question, because liquid water is essential for the aqueous systems that maintain life. Every astronaut has felt awe at seeing our beautiful blue orb from space. A biologist peering at the fabulous watery world of a living cell probably feels the same way. A chemist is awed by the principles of equilibrium and their universal application to aqueous solutions wherever they occur. 

Water is necessary for life. Many plant and animal adaptations conserve water — the thick skin of desert cacti and the intricate structure of the mammalian kidney are just two examples. Planetary scientists look for evidence of hquid water when speculating about the possibility of life on other planets such as Mars or Jupiter s moon. Titan. 

On Earth, sulfur is nearly ubiquitous because of its connection with volcanic activity. Volcanoes and other hot spots, like Yellowstone National Park, emit sulfur-containing gases, notably sulfur dioxide (SO ). The gases cool and condense, eventually hardening into sulfur crystals and compounds, the purest being lemon yellow in color. (Extraterrestrial sulfur atoms, and SO, have been also detected in the atmosphere of one of Jupiter s moons, lo, which boasts numerous active volcanoes.)... 

Miles beneath the Antarctic ice sheets there are lakes that have been secluded for millions of years. The conditions within these lakes are similar to what may exist beneath the ice sheets of Jupiter s moon Europa. Evidence suggests that these Antarctic lakes may contain microscopic life. If true, this adds to the possibility of I ife forms on Europa. For current information, enter Lake Vostok" into your Internet search engine. 

The twelfth man to set foot on the Moon in December, 1972, was a scientist. The first eleven were military pilots, but Harrison H. Schmitt was a professional geologist who later learned to fly aircraft On October 6, 2008, astronomer Richard Kowalski discovered that a small asteroid was headed for an impact with Earth. Later calculations predicted that it would hit within the next thirteen hours somewhere in the Sudan. It did, and by December, more than forty-seven meteorite fragments had been collected. In the search for extraterrestrial life. Mars always seemed the most promising place to look. However, strong evidence of warm oceans of water beneath the icy surface of Jupiter s moon Europa make it the more likely location for life. 

Rapid mixing of two chemically distinct fluids yields a solution that is, at least temporarily, out of thermodynamic equilibriirm. Here, we propose the formation of a hydrothermal solution that is the product of late Hadean vent fluid mixing irrto late Hadean seawater. In this mixed solution, diseqttihbria among redox serrsitive compoimds represent an energetic drive for the abiotic synthesis of or rric compounds. Similar mixing scenarios have been used effectively to model the energetic yields of chemolithotrophic metabolisms on Earth (21), Mars (38, 39), and Jupiter s moon Europa (40), and to evaluate the... 

The next most likely possibility is cometary delivery of the atmosphere but again there are some problems with the isotope ratios, this time with D/H. The cometary D/H ratios measured in methane from Halley are 31 3 x 10-5 and 29 10 x 10-5 in Hayuatake and 33 8 x 10-5 in Hale-Bopp, whereas methane measurements from Earth of the Titan atmosphere suggest a methane D/H ratio of 10 5 x 10-5, which is considerably smaller than the ratio in the comets. The methane at least in Titan s atmosphere is not exclusively from cometary sources. Degassing of the rocks from which Titan was formed could be a useful source of methane, especially as the subnebula temperature around Saturn (100 K) is somewhat cooler than that around Jupiter. This would allow volatiles to be more easily trapped on Titan and contribute to the formation of a denser atmosphere. This mechanism would, however, apply to all of Saturn s moons equally and this is not the case. 

Saturn is the second-largest planet in the solar system, after Jupiter. Its equatorial radius is 37,448 miles (60,268 km), about nine times that of Earth, and its mass is 568.46 x 1024 kg, about 95 times that of Earth. As of early 2007, scientists had found 56 satellites of Saturn, the largest of which is Titan, with a radius of 8,448 feet (2,575 km, about 50 percent larger than that of Earth s Moon), and a mass of 1,345.5 x IO20 kg (about twice that of the Moon). Saturn s density is 0.687 g/cm3, less than that of water. This fact means that (if one could find a body of water large enough) Saturn would float on water. It is the only planet with a density less than that of water. 

The Roche Urn it was first described by Edouard Roche in 1848. It is the closest distance a body held together by self-gravity can come to a planet without being pulled apart by the planet s tidal (gravity) force. As a result, large moons cannot survive inside the Roche Limit. On July 7,1992, Comet Shoemaker-Levy 9 broke apart into 21 pieces due to tidal forces when it passed within Jupiter s Roche Limit on the subsequent pass, each of the comet s pieces collided with Jupiter. 

Alkanes have the general molecular formula C 2n+i The simplest one, methane (CH4), is also the most abundant. Large amounts are present in our atmosphere, in the ground, and in the oceans. Methane has been found on Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto, and even on Halley s Comet. About 2-8% of the atmosphere of Titan, Saturn s largest moon, is methane. When it rains on Titan, it rains methane. 

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