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Posts Tagged ‘moons in our solar system’

Largest Solar System Moon Detailed In Geologic Map

February 13, 2014 Leave a comment

Image credit: USGS Astrogeology Science Center/Wheaton/NASA/JPL-Caltech

Image credit: USGS Astrogeology Science Center/Wheaton/NASA/JPL-Caltech

More than 400 years after its discovery by astronomer Galileo Galilei, the largest moon in the solar system – Jupiter’s moon Ganymede – has finally claimed a spot on the map.

More than 400 years after its discovery by astronomer Galileo Galilei, the largest moon in the solar system – Jupiter’s moon Ganymede – has finally claimed a spot on the map.

A group of scientists led by Geoffrey Collins of Wheaton College has produced the first global geologic map of Ganymede, Jupiter’s seventh moon. The map combines the best images obtained during flybys conducted by NASA’s Voyager 1 and 2 spacecraft (1979) and Galileo orbiter (1995 to 2003) and is now published by the U. S. Geological Survey as a global map. It technically illustrates the varied geologic character of Ganymede’s surface and is the first global, geologic map of this icy, outer-planet moon. The geologic map of Ganymede is available for download here.

“This map illustrates the incredible variety of geological features on Ganymede and helps to make order from the apparent chaos of its complex surface,” said Robert Pappalardo of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “This map is helping planetary scientists to decipher the evolution of this icy world and will aid in upcoming spacecraft observations.”

Link To Full Story

Magnetic Shielding Of Exomoons: To Be Or Not To Be

September 10, 2013 Leave a comment

A new study on magnetic fields around extrasolar giant planets sheds first light on the magnetic environment of extrasolar moons. The work, authored by René Heller of the Department of Physics and Astronomy at McMaster University (Canada) and Jorge I. Zuluaga of the FACom group in the Institute of Physics of the University of Antioquia (Colombia) is the first to explore the complex magnetic environment of exomoons and its impact on the habitability of these peculiar bodies.

Regrettably the results are not completely encouraging. Even the most massive moons that can be expected from a formation point of view will be small compared to Earth. Thus, the only possibility these moons can be magnetically protected from the stellar and cosmic high-energy radiation is that they are encoated by their giant planet’s magnetosphere. Yet, in orbits close to the planet, these moons can be subject to enormous tidal heating, potentially making them uninhabitable. These results represent just the beginning of an interesting research branch, which introduces a new key factor for the habitability of those “Pandora”-like environments.

Probably the first image that comes to our minds when thinking of an inhabitated extrasolar moon shows the beautiful landscapes of Pandora, the hypothetical moon of James Cameron’s movie Avatar. But the environments of extrasolar moons seem to be less favored than the idealized version shown on the big screen. Even if located around planets in the stellar “Habitable Zone”, where the amount of incoming light allows for the existence liquid water and hence life, exomoons are subject to a number of other perturbing effects making things harsher for life than previously thought.

Full Story: http://urania.udea.edu.co/sitios/facom/press.php?_inicomp=3&_numcomp=1&#

NASA Hubble Finds New Neptune Moon


NASA’s Hubble Space Telescope has discovered a new moon orbiting the distant blue-green planet Neptune, the 14th known to be circling the giant planet.

The moon, designated S/2004 N 1, is estimated to be no more than 12 miles across, making it the smallest known moon in the Neptunian system. It is so small and dim that it is roughly 100 million times fainter than the faintest star that can be seen with the naked eye. It even escaped detection by NASA’s Voyager 2 spacecraft, which flew past Neptune in 1989 and surveyed the planet’s system of moons and rings.

Mark Showalter of the SETI Institute in Mountain View, Calif., found the moon July 1, while studying the faint arcs, or segments of rings, around Neptune. “The moons and arcs orbit very quickly, so we had to devise a way to follow their motion in order to bring out the details of the system,” he said. “It’s the same reason a sports photographer tracks a running athlete — the athlete stays in focus, but the background blurs.”

Full Story: http://www.nasa.gov/content/nasa-hubble-finds-new-neptune-moon/#.UeQxij44XB4
Also: http://hubblesite.org/newscenter/archive/releases/2013/30/full/

Titan, Saturn’s Largest Moon, Icier Than Thought, Say Stanford Scientists

December 8, 2012 Leave a comment

A new analysis of topographic and gravity data from Titan, the largest of Saturn’s moons, indicates that Titan’s icy outer crust is twice as thick as has generally been thought.

Scientists have long suspected that a vast ocean of liquid water lies under the crust. The new study suggests that the internally generated heat that keeps that ocean from freezing solid depends far more on Titan’s interactions with Saturn and its other moons than had been suspected.

Titan has long intrigued scientists because of its similarities to the Earth. Like Earth, Titan appears to have a layered structure, crudely similar to the concentric layers of an onion, albeit far less edible. “Titan probably has a core that is a mixture of ice and rock,” said Howard Zebker, a professor of geophysics and of electrical engineering at Stanford University. The core is overlain by the ocean and icy crust.

Full Story: http://news.stanford.edu/pr/2012/pr-titan-saturn-moon-120312.html

Enceladus Plume Is A New Kind Of Plasma Laboratory


PASADENA, Calif. – Recent findings from NASA’s Cassini mission reveal that Saturn’s geyser moon Enceladus provides a special laboratory for watching unusual behavior of plasma, or hot ionized gas. In these recent findings, some Cassini scientists think they have observed “dusty plasma,” a condition theorized but not previously observed on site, near Enceladus.

Data from Cassini’s fields and particles instruments also show that the usual “heavy” and “light” species of charged particles in normal plasma are actually reversed near the plume spraying from the moon’s south polar region. The findings are discussed in two recent papers in the Journal of Geophysical Research.

“These are truly exciting discoveries for plasma science,” said Tamas Gombosi, Cassini fields and particles interdisciplinary scientist based at the University of Michigan, Ann Arbor. “Cassini is providing us with a new plasma physics laboratory.”

Full Story: http://www.jpl.nasa.gov/news/news.cfm?release=2012-149

How the Equatorial Ridge on Saturn’s Moon Iapetus Formed

March 29, 2012 Leave a comment

Saturn’s moon Iapetus is one of the most unusual moons in our solar system. Perhaps the most bizarre feature of Iapetus is its equatorial ridge, a 20-km (12.4-mi) high, 200-km (124-mi) wide mountain range that runs exactly along the equator, circling more than 75 percent of the moon. No other body in the solar system exhibits such a feature, and as Dombard et al. show, previous models have been unable to adequately explain how the ridge formed.

The authors now propose that the ridge formed from an ancient giant impact that produced a subsatellite around Iapetus. Tidal interactions with Iapetus ultimately led to orbital decay, eventually bringing the subsatellite close enough that the same forces tore it apart, forming a debris ring around Iapetus. Material from this debris ring then rained down on Iapetus, creating the mountain ring along the equator.

Full Story: http://www.agu.org/news/press/jhighlight_archives/2012/2012-03-29.shtml#four