A Watery, Extraterrestrial Ocean Is Submerged Beneath Enceladus’s Blankets of Ice
by Allison Eck
Move over, Mars. In the search for extraterrestrial life, moons are now in the limelight.
Enceladus, one of the Ringed Planet’s icy and austere orbiters has been on astronomers’ shortlist of potential hosts of alien life, especially since they discovered geysers of ice crystals shooting out of its south pole in 2005. They hypothesized that a deep ocean the size of Lake Superior sits underneath its highly tectonic and veiny surface, potentially feeding those gushers.
Normally, liquid water couldn’t exist that far out in the solar system, but the gravitational pull of Enceladus’s neighbor, Dione, bends the icy moon’s outer layer, creating heat through friction. NASA’s Cassini spacecraft has repeatedly flown by the surface of Enceladus to better understand the temperature dynamics that create these explosive geysers…
(read more: Nova Next - PBS)

A Watery, Extraterrestrial Ocean Is Submerged Beneath Enceladus’s Blankets of Ice

by Allison Eck

Move over, Mars. In the search for extraterrestrial life, moons are now in the limelight.

Enceladus, one of the Ringed Planet’s icy and austere orbiters has been on astronomers’ shortlist of potential hosts of alien life, especially since they discovered geysers of ice crystals shooting out of its south pole in 2005. They hypothesized that a deep ocean the size of Lake Superior sits underneath its highly tectonic and veiny surface, potentially feeding those gushers.

Normally, liquid water couldn’t exist that far out in the solar system, but the gravitational pull of Enceladus’s neighbor, Dione, bends the icy moon’s outer layer, creating heat through friction. NASA’s Cassini spacecraft has repeatedly flown by the surface of Enceladus to better understand the temperature dynamics that create these explosive geysers…

(read more: Nova Next - PBS)

Titan Tech: Lightweight Drone Could Explore Saturn Moon

by Elizabeth Howell

Sailing the soupy atmosphere of Titan, Saturn’s largest natural satellite, an interplanetary balloon could one day release a small drone to explore the moon’s swamp-like surface.

The so-called “Titan Aerial Daughtercraft” mission concept recently received a $100,000 Phase 1 grant from the NASA Innovative Advanced Concepts program, a sort of sandbox for the agency to explore far-out and futuristic ideas.

As part of this proposed mission, a quadcopter drone would “jump” from a mothership-type balloon to explore the surface of Titan; the drone would then return to the balloon to recharge for the night, the researchers said. Both vehicles would be used to investigate Titan’s hydrogen- and carbon-rich environment, which some scientists think resembles the composition of Earth’s atmosphere early in its history…

(read more: Live Science)

images: illustration - Larry Matthies/NASA; photos - NASA/JPL/University of Arizona

Mysterious Magic Island Appears on Saturn’s Moon Titan

Now you don’t see it. Now, you do. And now you don’t see it again. Astronomers have discovered a bright, mysterious geologic object – where one never existed – on Cassini mission radar images of Ligeia Mare, the second-largest sea on Saturn’s moon Titan. Scientifically speaking, this spot is considered a “transient feature,” but the astronomers have playfully dubbed it “Magic Island.”

Reporting in the journal Nature Geoscience June 22, the scientists say this may be the first observation of dynamic, geological processes in Titan’s northern hemisphere.

"This discovery tells us that the liquids in Titan’s northern hemisphere are not simply stagnant and unchanging, but rather that changes do occur," said Jason Hofgartner, a Cornell University graduate student in the field of planetary sciences, and the paper’s lead author. "We don’t know precisely what caused this ‘magic island’ to appear, but we’d like to study it further."…

(read more: PhysOrg)

image: Credit: NASA/JPL-Caltech/ASI/Cornell

How Tall Are Eruptions on Io and Venus?

by Erik Klemetti

Earth does not hold the monopoly on active volcanism in the solar system. In fact, Earth isn’t even the most volcanically active body in the solar system. Although we have abundant volcanism, to the tune of hundreds to thousands of active and potentially active volcanoes, if you look at the amount of land surface covered by the deposits of recent volcanism, Earth’s volcanism is confined to fairly small areas.

Even so, volcanism likely played a vital role in getting life started on the Earth — and maybe it is the driving force in other parts of the solar system. The manifestation of volcanism on other planets is different than on Earth as well — some places produce giant eruption plumes (like on Io) and some might produce very small plumes (like at the newly-identified potentially active volcanoes on Venus), so why are they so different?

Look at a place like Jupiter’s moon, Io. This plucky little moon is covered almost wall-to-wall with geologically-recent volcanic deposits (see above) thanks to the tidal forces exerted on it by Jupiter’s gravity. When New Horizons passed by Io in 2007, the spacecraft (headed to Pluto-Charon) captured a sequence of frames that showed the giant volcanic plume from TvashtarPatera (along with some fainter plumes from Masubi and Zal; see below)…

(read more: Wired Science)

images: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute

Behold the first geological map of Ganymede, Jupiter’s largest moon

by Lauren Davis

Four hundred years ago, Galileo Galilei observed Ganymede in orbit around Jupiter. This week, a team of planetary scientists unveiled the first global geological map of our solar system’s largest moon.

Using images obtained by NASA’s Voyager 1 and 2 spacecraft and the Galileo orbiter, a team led by Geoffrey Collins of Wheaton College pieced together a mosaic image of the planet, giving us our first complete image of the geological features of the satellite. Above, you can see the moon centered at 200 west longitude. The darker areas represent the very old and heavily cratered region of Ganymede, while the lighter areas are somewhat younger regions marked with grooves and ridges…

(read more: io9)   (… and a 2nd look.)

images: NASA-JPL

Europa New Frontiers Mission? (Or why I like the Europa Clipper concept even more now)
 by Van Kane
Jupiter’s moon Europa has been a priority destination for NASA’s planetary program since the mid-1990s. With a deep ocean trapped beneath an icy shell on top and the rocky surface below, Europa is believed to have the chemicals and energy needed to host life. Over the course of almost two decades, I’ve seen plans for a better, really cheaper, faster mission that just needed a lot of new technology to be developed.
As if to balance that plan out, there was a plan for the planetary equivalent of a Battlestar Galactica mission that was both unaffordable and also required technology that still doesn’t exist. I thought we were close with the Jupiter Europa Orbiter (JEO, circa 2010) until new cost estimates showed that it, too, was unaffordable.
Now we have a proposed mission, the Europa Clipper, that doesn’t require substantial technology development and that has a cost estimate (~$2B) that puts it well within the cost range of NASA’s larger science missions. However, in today’s era of declining US federal budgets, the Clipper’s price tag is deemed unaffordable.
In a conversation with scientists on a NASA advisory panel, the head of the space agency’s Science program, John Grunsfeld discussed whether NASA should look at a Europa mission for half that of the Clipper mission. If it could be done, then a Europa mission could fit in the established New Frontiers program of planetary missions. (I want to emphasize that Grunsfeld’s conversation was informal and wasn’t announcing a policy decision.)…
(read more: Planetary Society)
image by NASA/JPL-CalTech

Europa New Frontiers Mission? (Or why I like the Europa Clipper concept even more now)

by Van Kane

Jupiter’s moon Europa has been a priority destination for NASA’s planetary program since the mid-1990s. With a deep ocean trapped beneath an icy shell on top and the rocky surface below, Europa is believed to have the chemicals and energy needed to host life. Over the course of almost two decades, I’ve seen plans for a better, really cheaper, faster mission that just needed a lot of new technology to be developed.

As if to balance that plan out, there was a plan for the planetary equivalent of a Battlestar Galactica mission that was both unaffordable and also required technology that still doesn’t exist. I thought we were close with the Jupiter Europa Orbiter (JEO, circa 2010) until new cost estimates showed that it, too, was unaffordable.

Now we have a proposed mission, the Europa Clipper, that doesn’t require substantial technology development and that has a cost estimate (~$2B) that puts it well within the cost range of NASA’s larger science missions. However, in today’s era of declining US federal budgets, the Clipper’s price tag is deemed unaffordable.

In a conversation with scientists on a NASA advisory panel, the head of the space agency’s Science program, John Grunsfeld discussed whether NASA should look at a Europa mission for half that of the Clipper mission. If it could be done, then a Europa mission could fit in the established New Frontiers program of planetary missions. (I want to emphasize that Grunsfeld’s conversation was informal and wasn’t announcing a policy decision.)…

(read more: Planetary Society)

image by NASA/JPL-CalTech

Icy Europa May Be First Alien World Found With Active Plate Tectonics
by Betsy Mason
Scientists may have spotted the first evidence for active plate tectonics on another world. Jupiter’s moon Europa is covered in an ice crust bearing scars that may reveal movement similar to that of Earth’s rocky plates.
Europa was already considered to be among the most scientifically intriguing bodies in the solar system and one of the most promising places to hunt for life in the solar system because of the liquid ocean that resides beneath its crust. If the latest findings turn out to be true, it could be another point in favor of the moon’s potential habitability by providing a way to get nutrients from the surface down into the ocean.
“What’s exciting is that this would be the only other place outside of Earth where a plate-tectonic-style system is occurring,” said planetary scientist Alyssa Rhoden, a NASA postdoctoral program fellow who studies Europa, but was not involved in the new research…
(read more: Wired Science)
photo: NASA/JPL/University of Arizona

Icy Europa May Be First Alien World Found With Active Plate Tectonics

by Betsy Mason

Scientists may have spotted the first evidence for active plate tectonics on another world. Jupiter’s moon Europa is covered in an ice crust bearing scars that may reveal movement similar to that of Earth’s rocky plates.

Europa was already considered to be among the most scientifically intriguing bodies in the solar system and one of the most promising places to hunt for life in the solar system because of the liquid ocean that resides beneath its crust. If the latest findings turn out to be true, it could be another point in favor of the moon’s potential habitability by providing a way to get nutrients from the surface down into the ocean.

“What’s exciting is that this would be the only other place outside of Earth where a plate-tectonic-style system is occurring,” said planetary scientist Alyssa Rhoden, a NASA postdoctoral program fellow who studies Europa, but was not involved in the new research…

(read more: Wired Science)

photo: NASA/JPL/University of Arizona

Saturn’s Moons Dance
Photo: NASA/JPL-Caltech/Space Science Institute
A quintet of Saturn’s moons dance elegantly above the planet’s famed rings in this photo taken by the Cassini spacecraft and released November 4.In orbit around the ringed planet since 2004, Cassini has offered unparalleled views of Saturn’s rings and moons, including this picture shot from slightly above the plane of the rings.
On the right, the closest moon is Rhea, which is Saturn’s second-largest satellite, and in the center is Enceladus, shining brightly with frost vented from its south pole geysers.
(via: National Geo)

Saturn’s Moons Dance

Photo: NASA/JPL-Caltech/Space Science Institute

A quintet of Saturn’s moons dance elegantly above the planet’s famed rings in this photo taken by the Cassini spacecraft and released November 4.In orbit around the ringed planet since 2004, Cassini has offered unparalleled views of Saturn’s rings and moons, including this picture shot from slightly above the plane of the rings.

On the right, the closest moon is Rhea, which is Saturn’s second-largest satellite, and in the center is Enceladus, shining brightly with frost vented from its south pole geysers.

(via: National Geo)

Cassini gets new views of Titan’s land of lakes (Phys.org) —With the sun now shining down over the north pole of Saturn’s moon Titan, a little luck with the weather, and trajectories that put the spacecraft into optimal viewing positions, NASA’s Cassini spacecraft has obtained new pictures of the liquid methane and ethane seas and lakes that reside near Titan’s north pole. The images reveal new clues about how the lakes formed and about Titan’s Earth-like “hydrologic” cycle, which involves hydrocarbons rather than water… (read more) Image: NASA/JPL-Caltech/University of Arizona/Univ. of Idaho


Cassini gets new views of Titan’s land of lakes

(Phys.org) —With the sun now shining down over the north pole of Saturn’s moon Titan, a little luck with the weather, and trajectories that put the spacecraft into optimal viewing positions, NASA’s Cassini spacecraft has obtained new pictures of the liquid methane and ethane seas and lakes that reside near Titan’s north pole. The images reveal new clues about how the lakes formed and about Titan’s Earth-like “hydrologic” cycle, which involves hydrocarbons rather than water… (read more)

Image: NASA/JPL-Caltech/University of Arizona/Univ. of Idaho

The Moon May Be Younger That We Thought

by Annalee Newitz

The violent history of the Earth’s Moon just gave rise to a new mystery. At a Royal Society special meeting today, planetary scientist Rick Carlson announced that the Moon is a few hundred million years younger than we thought. This could change our understanding of how the Earth formed, too.

Carlson reported that new methods for dating rocks from the Moon’s crust or regolith have placed its birth between 4.4 and 4.45 billion years ago. Previously, scientists placed its origin at 4.56 billion years ago. The Moon was formed when a Mars-sized body smashed into the Earth, reducing part of our planet to liquid rock and shooting debris into orbit that slowly cooled and coalesced into the Moon…

(read more: io9)

illustrations by Ron Miller


Infrared Saturn and Titan
Gemini North infrared image of Saturn and Titan (at about 6 o’clock position). Image obtained on May 7, 2009 (5:31 UTC), using the Altair adaptive optics system with the Near-infrared imager (NIRI). Color composite image made using data from three infrared filters (K’ [2.0-2.1 microns], h210 [2.12 mircon narrowband], and bracket gamma [2.17 micron narrowband]), field of view is about 40 arcseconds across.
At the edges of Saturn’s ring, the F-ring is faintly visible. The F-ring was discovered in images from the Pioneer 11 spacecraft in 1979 and is normally not apparent in images taken with ground-based telescopes. Also apparent are several of Saturn’s smaller moons.
Image: Gemini Observatory/AURA/Henry Roe, Lowell Observatory/Emily Schaller, Insitute for Astronomy, University of Hawai’i [high-resolution]
Caption: National Science Foundation

(via: Wired Science)

(via: Wired Science)

somuchscience
The Galilean moons are the four moons of Jupiter discovered by Galileo Galilei in January 1610. They are the largest of the 67 moons of Jupiter and derive their names from the lovers of Zeus: Io, Europa, Ganymede, and Callisto. They are among the most massive objects in the Solar System outside the Sun and the eight planets, with radii larger than any of the dwarf planets. The three inner moons – Ganymede, Europa, and Io – participate in a 1:2:4 orbital resonance…
(read more: Wikipedia)

The Galilean moons are the four moons of Jupiter discovered by Galileo Galilei in January 1610. They are the largest of the 67 moons of Jupiter and derive their names from the lovers of Zeus: Io, Europa, Ganymede, and Callisto. They are among the most massive objects in the Solar System outside the Sun and the eight planets, with radii larger than any of the dwarf planets. The three inner moons – Ganymede, Europa, and Io – participate in a 1:2:4 orbital resonance

(read more: Wikipedia)

A true-color image of Io, one of the moons of Jupiter, taken by the Galileo spacecraft. The dark spot just left of center is the erupting volcano Prometheus. Whitish plains on either side of it are coated with volcanically emplaced sulfur dioxide frost, while yellower regions are encrusted with a higher proportion of sulfur.
Photo: NASA                                                            via: Wikipedia

A true-color image of Io, one of the moons of Jupiter, taken by the Galileo spacecraft. The dark spot just left of center is the erupting volcano Prometheus. Whitish plains on either side of it are coated with volcanically emplaced sulfur dioxide frost, while yellower regions are encrusted with a higher proportion of sulfur.

Photo: NASA                                                            via: Wikipedia