Cassini to make a double play
December 12, 2011 By Jia-Rui C. Cook
A quartet of Saturn's moons, from tiny to huge, surround and are embedded within the planet's rings in this Cassini composition. Credit: NASA/JPL-Caltech/Space Science Institute
(PhysOrg.com) -- In an action-packed day and a half, NASA's Cassini spacecraft will be making its closest swoop over the surface of Saturn's moon Dione and scrutinizing the atmosphere of Titan, Saturn's largest moon.
The closest approach to Dione, about 61 miles (99 kilometers) above the surface, will take place at about 1:39 a.m. PST (4:39 a.m. EST) on Dec. 12. One of the questions Cassini scientists will be asking during this flyby is whether Dione's surface shows any signs of activity. Understanding Dione's internal structure will help address that question, so Cassini's radio science instrument will learn how highly structured the moon's interior is by measuring variations in the moon's gravitational tug on the spacecraft. The composite infrared spectrometer instrument will also look for heat emissions along fractures on the moon's surface.
Cassini will also be probing whether Dione, like another Saturnian moon, Rhea, has a tenuous atmosphere. Scientists expect a Dionean atmosphere - if there is one - to be much more ethereal than even Rhea's. Research published in journal Geophysical Research Letters and led by Sven Simon, a Cassini magnetometer team member at the University of Cologne, Germany, found magnetic field disturbances around Dione, hinting at a tenuous atmosphere. But scientists hope to get stronger confirmation by "tasting" the space around the moon with Cassini's ion and neutral mass spectrometer.
On Cassini's journey out from Dione toward Titan, the imaging science subsystem will turn back to look at Dione's distinctive, wispy fractures and a ridge called Janiculum Dorsa.
Cassini will approach within about 2,200 milles (3,600 kilometers) of the Titan surface, at about 12:11 p.m. PST (3:11 PM EST) on Dec. 13. At Titan, the composite infrared spectrometer will be making measurements to understand how the seasonal transition from spring to summer affects wind patterns in the atmosphere near Titan's north pole. It will also search for mist.
The visual and infrared mapping spectrometer and imaging science subsystem will be observing the same equatorial deserts where the imaging science subsystem saw sudden and dramatic surface changes last year, when Titan was experiencing early northern spring. One possibly theory is that rainstorms caused these changes. As Cassini recedes from Titan, the imaging cameras will also continue to observe the moon for another day to monitor any new weather systems.
Provided by
JPL/NASA
-
From lemons to lemonade: Reaction uses carbon dioxide to make carbon-based semiconductor,
32 comments
-
Thioridazine kills cancer stem cells in human while avoiding toxic side-effects of conventional cancer treatments,
3 comments
-
SpaceX private rocket blasts off for space station (Update),
42 comments
-
Climate scientists say they have solved riddle of rising sea,
31 comments
-
SpaceX capsule has 'new car' smell, astronauts say (Update),
4 comments
-
Distance of planets from stars and revolution
7 hours ago
-
revamping general concept and cosmological principle
May 25, 2012
-
Transiting Exoplanet Light Curve
May 25, 2012
-
Math behind Theoretical Physics
May 24, 2012
-
Do we know whats at the center of galaxies yet?
May 23, 2012
-
Structure of the Milky Way?
May 20, 2012
- More from Physics Forums - General Astronomy
More news stories
Land and sea species differ in climate change response: study
(Phys.org) -- Marine and terrestrial species will likely differ in their responses to climate warming, new research by Simon Fraser University and Australia’s University of Tasmania has found.
5 hours ago |
3.7 / 5 (3) |
5
|
Yale study concludes public apathy over climate change unrelated to science literacy
Are members of the public divided about climate change because they don't understand the science behind it? If Americans knew more basic science and were more proficient in technical reasoning, would public consensus match ...
7 hours ago |
4.8 / 5 (5) |
19
|
10 million years needed to recover from mass extinction
It took some 10 million years for Earth to recover from the greatest mass extinction of all time, latest research has revealed.
Space & Earth / Earth Sciences
7 hours ago |
4 / 5 (4) |
1
|
Sophisticated simulations predict future warming
The chances of our planet being hit by a global warming of 3 degrees Celsius by 2050 is as likely as it being hit by an increase of 1.4 degrees, new research shows. Presented in the journal Nature Geoscience, the British study ...
Space & Earth / Earth Sciences
May 22, 2012 |
4.1 / 5 (10) |
51
Aliens don't want to eat us, says former SETI director
Alien life probably isn’t interested in having us for dinner, enslaving us or laying eggs in our bellies, according to a recent statement by former SETI director Jill Tarter.
Space & Earth / Space Exploration
May 25, 2012 |
4.4 / 5 (15) |
41
Stunning image of smallest possible five-ringed structure
Scientists have created and imaged the smallest possible five-ringed structure – about 100,000 times thinner than a human hair – and you'll probably recognise its shape.
'Unzipped' carbon nanotubes could help energize fuel cells, batteries
Multi-walled carbon nanotubes riddled with defects and impurities on the outside could replace some of the expensive platinum catalysts used in fuel cells and metal-air batteries, according to scientists at ...
Change in developmental timing was crucial in the evolutionary shift from dinosaurs to birds: study
At first glance, it's hard to see how a common house sparrow and a Tyrannosaurus Rex might have anything in common. After all, one is a bird that weighs less than an ounce, and the other is a dinosaur that ...
Computer model used to pinpoint prime materials for efficient carbon capture
When power plants begin capturing their carbon emissions to reduce greenhouse gases – and to most in the electric power industry, it's a question of when, not if – it will be an expensive undertaking.
T cells 'hunt' parasites like animal predators seek prey, study shows
By pairing an intimate knowledge of immune-system function with a deep understanding of statistical physics, a cross-disciplinary team at the University of Pennsylvania has arrived at a surprising finding: T cells use a movement ...
Scientists develop ultra-sensitive test that detects diseases in their earliest stages
Scientists have developed an ultra-sensitive test that should enable them to detect signs of a disease in its earliest stages, in research published today in the journal Nature Materials.
Dec 12, 2011
Rank: 1.3 / 5 (6)
Dec 12, 2011
Rank: 1 / 5 (10)
Guys at NASA and JPL have to at least LOOK busy to justify their salary.
He had to at least ACT like they discovered anything worthwhile, so he could keep that salary.
Face it, most of the space exploration we've done is a complete waste of money until somebody produces scalable FUSION or COLD FUSION reactors OR some other exotic, unknown nuclear or quantum energy source.
The resources out there are worthless without the energy to use them.
The science is pretty mundane, and nothing revolutionary since at least 20 years ago.
Dec 12, 2011
Rank: 1.8 / 5 (4)
Dec 12, 2011
Rank: 1 / 5 (50)
It's not as simple as just dropping packages off on the way. Those packages are also going the same speed as the mothership.
To put it simply, we just don't have the technology or more importantly the funding to accomplish such missions.
The voyagers were not tasked with turning around. This is the sticking point you aren't aware of.
Also I'm pretty sure every probe we've built that has solar escape velocity has a voyager-type endgame assuming they last long enough. New Horizons (the Pluto probe) will have an end mission much like that of the Voyagers.
And Cassini is quite the wrong project for you to wage your criticisms against because it contained an orbiter. That's where these pictures are from.