Posts tagged with "Saturn"
Monday, 5. March 2007, 15:36:06
Stargazing, Saturn, Astronomy
Saturn and some of its major moonsMagnitude: + 0.1
Angular Diameter: 19.8 arc-seconds (disk), 44.9 arc-seconds (visible rings)Saturn, just past opposition, is riding high in the sky virtually all night. The planet lies in Leo, roughly 10° from that constellation's brightest star, Regulus. On the evening of March 1st, the Moon pairs with Saturn as they both rise in the east after sunset; only 1/2° (barely a Moon-width) separates them.
March is an excellent month for observing Saturn through a telescope; the planet quickly rises above the horizon to provide the best views. The rings, of course, are its most noticeable feature. A small instrument will reveal the broad, bright A and B rings, and the narrow Cassini Division between them. A larger instrument may reveal the much fainter inner C ring, and perhaps some subtle atmospheric bands on the planet's disk. Finally, of course, a handful of moons are visible in amateur telescopes: Titan, Rhea, Tethys, Dione, and perhaps Iapetus and tiny Enceladus.RELATED LINKS:*
Positions of major moons*
CASSINI AT SATURN - Present Position*
Ephemerides*
Interactive Sky Chart*
This month´s starchart
Friday, 2. March 2007, 12:02:21
Saturn, Cassini, Images, Astronomy
PASADENA, Calif. - The international Cassini spacecraft has beamed back to Earth never-before-seen angles of Saturn from high above and below its majestic rings. The planet is fully surrounded by the rings in images released Thursday by NASA.
This photo released by NASA Thursday, March 1, 2007, shows an image of the planet Saturn obtained with the Cassini spacecraft wide-angle camera on Jan. 19, 2007, as the planet's shadow stretches completely across the rings. The view is a mosaic of 36 images taken over the course of about 2.5 hours, as Cassini scanned across the entire main ring system. (AP Photo/NASA, JPL)
"Finally, here are the views that we've waited years for," Cassini scientist Carolyn Porco of the Space Science Institute in Boulder, Colo., said in a statement. "It just doesn't look like the same place. It's so utterly breathtaking, it almost gives you vertigo," Porco said.
Cassini snapped the images while in a highly inclined orbit during the past two months. The $3.3 billion Cassini mission, funded by NASA and the European and Italian space agencies, was launched in 1997. It is managed by NASA's Jet Propulsion Laboratory in Pasadena.
Friday, 12. May 2006, 03:59:25
Astronomy, Saturn, Titan
By
Kenneth Chang, New York Times
Published: May 9, 2006
A few years ago, many planetary scientists entertained visions of Titan, a Saturn moon, awash in oceans — not of water, but of ethane, a hydrocarbon gas that can condense to liquid at the surface, where the temperatures average minus-290 degrees Fahrenheit.
Top, Science; Earth Sciences and Image Analysis Laboratory/NASA
An image of Titan, a moon of Saturn, top, shows lines of dunes like those in the Namib Desert in Africa, above.But images from NASA's Cassini spacecraft now show the opposite picture: the equatorial regions appear arid, with vast seas of sand dunes like those in the Sahara. That is all the more remarkable because Titan almost certainly does not have sand like the sand in the Sahara.
The radar images, reported in the current issue of the journal Science, show parallel, east-west lines of dunes, which are spaced about a mile apart, reach more than 300 feet high and run up to 930 miles long.
The dunes raise two questions: What are the grains made of? What is creating the wind to blow them around?
Because Titan is so far from the Sun, scientists had expected the air there to be still, with little energy from sunlight to power the winds. Now, however, they think gravitational tides produced by Titan's elliptical orbit around Saturn may be enough to drive winds averaging one mile per hour, and gusts would be faster. With Titan's lesser gravity and thicker air, that is enough to blow the sand around.
As for the sand itself, Titan's grains are most likely bits of water ice or organic solids, not silicates like the sand on Earth. (Titan is roughly half rock and half ice, and the rocky material like silicates probably sank to the moon's middle.)
Despite the very different conditions on Titan, the parallel lines of dunes look virtually the same as those in the Sahara or in the Namib Desert in Africa.
"Somehow all this stuff cancels out," said Ralph D. Lorenz, a scientist at the University of Arizona and an author of the Science paper, "and it gives you the same landscape you find on Earth."
Monday, 8. May 2006, 09:47:31
Astronomy, Saturn, Moons
Pristine dunes on the surface of Titan.Saturn's moon Titan has huge regions covered with dunes, possibly made out of ice crystals, sand or some other unknown material, international space scientists reported on Thursday.
FULL STORYRelated Links:•
So, exactly how long is a day on Saturn?•
Saturn’s Rings Created by Collision • Gallery:
Saturn's rings
Thursday, 20. April 2006, 11:18:38
Gemini, Saturn, Astronomy, Mars
Gemini is one of the easiest constellations to see, as it does resemble a pair of twins. Connect the stars in the western sky this month with imaginary lines and two figures magically appear. You won't need a telescope to see Pollux and Castor, the brilliant stars at the twins' heads and for whom they are named. You should also be able to see ruddy Mars, which appears near Castor's foot at mid-month and traverses the torso of each twin as the month progresses.
If you do aim your telescope at Mars, above the two visible stars marking Castor's foot, you'll see dozens of stars in a cluster called Messier 35 or simply M35, named in the 18th century by Charles Messier. In a very dark sky, you may even be able to see the cluster with unaided eyes. With a telescope, you may also see smaller and fainter NGC 2158, another cluster sharing the same eyepiece field of view as Messier 35. Though these two clusters are nearly the same size, Messier 35 is closer, about 16 light years distant from Earth, and appears larger than NGC 2158, which is 10 times older and six times further away.
Meanwhile, Saturn has been hovering near another star cluster, Messier 44, the Beehive cluster for several months. Look for Saturn higher in the sky, above the head of the other Gemini twin, Pollux. Watch Saturn and Mars over the next month. They will move closer together near the Beehive cluster by late May.
Editors Note: M35 is actually northeast of the other cluster. The view in the image of the two clusters is inverted to match most telescope views.
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Monday, 13. March 2006, 00:30:23
News, Saturn, Enceladus
March 10, 2006 based on a NASA release 
NASA's Cassini spacecraft may have found evidence of liquid water reservoirs that erupt in Yellowstone-like geysers on Saturn's moon Enceladus. The rare occurrence of liquid water so near the surface raises many new questions about the mysterious moon.
This finding and others are reported by the Cassini Imaging Science Team in the journal Science.
"We realize that this is a radical conclusion -- that we may have evidence for liquid water within a body so small and so cold," said Carolyn Porco, Cassini imaging team leader at the Space Science Institute in Boulder, Colorado, and the lead author of the Science report. "However, if we are right, we have significantly broadened the diversity of solar system environments where we might possibly have conditions suitable for living organisms." 
High-resolution Cassini images show icy jets and towering plumes ejecting large quantities of particles at high speed. Scientists examined several models to explain the process, and they determined there are too many particles being released from the south pole for the source to be merely frozen mist condensing out of a plume of water vapor. They don’t think the particles are being blown off by jets of water vapor that arise from warm ice, either. Instead, scientists have found evidence for a much more exciting possibility. The jets might be erupting from near-surface pockets of liquid water above 0 degrees Celsius (32 degrees Fahrenheit), like cold versions of the Old Faithful geyser in Yellowstone. Recent Cassini images of Enceladus show fountain-like sources of a fine spray of material that towers above the south polar region. The image was taken looking more or less broadside at the 'tiger stripe' fractures observed in earlier Enceladus images and shows discrete and small-scale plumes above the limb of the moon. Credit: CICLOPS +
Full StoryRelated Articles+
Tiger, Tiger, Burning Bright+
Does Enceladus Govern Magnetospheric Dynamics at Saturn?+
Cassini probe may have found water on Saturn moon Enceladus+
Spacecraft could have found water on Saturn's moon
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