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719 results on '"Saturn (Planet) -- Observations"'

1. Saturn's disappearing rings

Subjects
Planetary rings -- Observations, Saturn (Planet) -- Observations
Abstract

Q | DO ASTRONOMERS HAVE ANY ESTIMATES OF WHEN SATURN'S RINGS WILL DISAPPEAR? Doug Kaupa Council Bluffs, Iowa A | All four of the solar system's giant planets have ring [...]

Published
2024

2. UH scientists discover massive energy imbalance on Saturn

Subjects
Climate models -- Research, Gas giants -- Observations, Saturn (Planet) -- Observations, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry, University of Houston -- Research
Abstract

Houston TX (SPX) Jun 21, 2024 A groundbreaking discovery by researchers at the University of Houston has revealed a massive energy imbalance on Saturn, shedding new light on planetary science [...]

Published
2024

3. A Saturn ring mirage: Averted vision can result in unexpected effects

Author

O'meara, Stephen James

Subjects
Planetary rings -- Observations, Saturn (Planet) -- Observations, Astronomy
Abstract

Roughly every 15 years, Earth passes through the plane of Saturn's rings, causing them to nearly disappear from view--not to mention generating a variety of other interesting phenomena. The next [...]

Published
2024

5. Saturn's tiny 'Death Star' moon may have hidden ocean

Author

Lagatta, Eric

Subjects
Cassini (Space probe) -- Usage, Ocean -- Observations, Saturn (Planet) -- Observations, Saturn probes -- Usage, News, opinion and commentary
Abstract

Byline: Eric Lagatta, USA TODAY The appearance of one of Saturn's smallest moons lends it the nickname 'Death Star,' but astronomers say new evidence suggests the world is, in fact, [...]

Published
2024

6. AUGUST 2021 See Jupiter and Saturn at opposition

Author

Ratcliffe, Martin and Ling, Alister

Subjects
Jupiter (Planet) -- Observations, Saturn (Planet) -- Observations, Alignments (Astronomy) -- Observations -- Forecasts and trends, Market trend/market analysis, Astronomy
Abstract

SKY THIS MONTH THE SOLAR SYSTEM'S CHANGING LANDSCAPE AS IT APPEARS IN EARTH'S SKY. BY MARTIN RATCLIFFE AND ALISTER LING On early August evenings, you'll find three rocky planets in [...]

Published
2021

7. Hubble finds Saturn's rings heating its atmosphere

Subjects
Hubble Space Telescope (Artificial satellite) -- Usage, Planetary rings -- Observations, Saturn (Planet) -- Observations, Atmosphere, Upper -- Observations, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Washington DC (SPX) Mar 31, 2023 The secret has been hiding in plain view for 40 years. But it took the insight of a veteran astronomer to pull it all [...]

Published
2023

8. Hubble captures the start of a new spoke season at Saturn

Subjects
Hubble Space Telescope (Artificial satellite) -- Usage, Astronomical research, Saturn (Planet) -- Observations, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Baltimore MD (SPX) Feb 10, 2023 New images of Saturn from NASA's Hubble Space Telescope herald the start of the planet's 'spoke season' surrounding its equinox, when enigmatic features appear [...]

Published
2023

9. Science news: Elements of life on a Saturn moon and how spaceflight affects the brain

Subjects
Brain research, Moon -- Observations, Space flight -- Health aspects, Saturn (Planet) -- Observations, General interest
Abstract

To listen to this broadcast, click here: http://www.npr.org/templates/transcript/transcript.php?storyId=1182520045 BYLINE: EMILY KWONG HOST: ARI SHAPIRO ARI SHAPIRO: It's time for some science news from our friends at NPR's Short Wave podcast. [...]

Published
2023

10. MARCH 2021: Late mornings, early evenings

Author

Ratcliffe, Martin and Ling, Alister

Subjects
Orbits -- Observations, Vesta (Asteroid) -- Observations, Mercury (Planet) -- Observations, Earth -- Rotation, Mars (Planet) -- Observations, Saturn (Planet) -- Observations, Astronomy
Abstract

THE SOLAR SYSTEM'S CHANGING LANDSCAPE AS IT APPEARS IN EARTH'S SKY. During March, Mars lingers in the evening sky as a wonderful bright object as it crosses Taurus. Most of [...]

Published
2021

11. Lowell Observatory points telescopes at Saturn during closest annual approach

Subjects
Telescope -- Usage, Astronomy -- Research, Saturn (Planet) -- Observations, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry, Lowell Observatory -- Research -- Equipment and supplies
Abstract

Flagstaff AZ (SPX) Aug 09, 2022 Saturn will soon be at its biggest and brightest of the year, and Lowell Observatory is celebrating with nightly public telescope viewing. For the [...]

Published
2022

12. Ocean on Moon of Saturn Has Ingredients for Life

Author

Miller, Katrina

Subjects
Ocean -- Observations, Enceladus (Satellite) -- Observations, Phosphates -- Analysis, Saturn (Planet) -- Observations, General interest, News, opinion and commentary
Abstract

Using data from the Cassini spacecraft, scientists discovered the presence of phosphates on icy Enceladus. Enceladus -- the sixth-largest of Saturn's 146 moons -- has a liquid ocean with a [...]

Published
2023

13. Saturn's Moons Knock Jupiter Off Its Pedestal

Author

O'Callaghan, Jonathan

Subjects
Satellites -- Observations -- Discovery and exploration, Jupiter (Planet) -- Observations, Saturn (Planet) -- Observations, General interest, News, opinion and commentary
Abstract

In the red corner, Jupiter, the largest planet orbiting our sun, which shaped our solar system with its gravitational bulk. In the blue corner, Saturn, the magnificent ringed world with [...]

Published
2023

16. Saturn reaches opposition - how to view the planet at its best

Subjects
Astronomy, Saturn (Planet) -- Observations, General interest
Abstract

To listen to this broadcast, click here: http://www.npr.org/templates/transcript/transcript.php?storyId=1117465759 HOST: MICHEL MARTIN MICHEL MARTIN: If you've got some free time this evening, we have a suggestion for something you might want [...]

Published
2022

17. The devil's in the details: What should you really look for through the eyepiece?

Author

Berman, Bob

Subjects
Observational astronomy -- Methods, Jupiter (Planet) -- Observations, Saturn (Planet) -- Observations, Astronomy
Abstract

You've heard the cliche about details. But it's celestially inaccurate, because details are where we usually discover the sublime--or, at least, they're what lure our attention. So, what is it [...]

Published
2021

18. A Report in Hebrew of a Bright Object in the Sky in 1473

Author

Goldstein, Bernard R.

Subjects
Puglia, Italy -- History, Auroras -- Observations, Saturn (Planet) -- Observations, Mars (Planet) -- Observations, Philosophy and religion, Science and technology
Abstract

The bright object (probably an auroral display) was observed in Lecce, Italy, and it is described briefly in this report, followed by a remark on a conjunction of Saturn and Mars that took place soon thereafter., Introduction New York, Jewish Theological Seminary of America, MS 2601, fol. 165b, contains a brief report of an unusually bright object in the sky observed in August 1473 in Lecce [...]

Published
2018

19. Experiments validate the possibility of helium rain inside Jupiter and Saturn

Subjects
Helium -- Distribution, Jupiter (Planet) -- Observations, Planets -- Atmosphere, Saturn (Planet) -- Observations, Company distribution practices, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Livermore CA (SPX) May 27, 2021 Nearly 40 years ago, scientists first predicted the existence of helium rain inside planets composed primarily of hydrogen and helium, such as Jupiter and [...]

Published
2021

20. Hubble Sees Changing Seasons on Saturn

Subjects
United States. National Aeronautics and Space Administration -- Reports, Hubble Space Telescope (Artificial satellite) -- Usage, Planets -- Atmosphere, Saturn (Planet) -- Observations, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Greenbelt MD (SPX) Mar 19, 2021 NASA's Hubble Space Telescope is giving astronomers a view of changes in Saturn's vast and turbulent atmosphere as the planet's northern hemisphere summer transitions [...]

Published
2021

21. Stargazers given once in-a-lifetime opportunity to see 'Great Conjunction' of Saturn and Jupiter

Subjects
Jupiter (Planet) -- Observations, Saturn (Planet) -- Observations, Alignments (Astronomy) -- Forecasts and trends, Market trend/market analysis, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Exeter UK (SPX) Dec 15, 2020 Budding astronomers will be given a once-in-a-lifetime opportunity to witness a truly special celestial event in the run-in to Christmas. This month, the gas [...]

Published
2020

22. Checking In With the Sun's Gas Giants

Author

Overbye, Dennis

Subjects
James Webb Space Telescope (Artificial satellite), Neptune (Planet) -- Observations, Jupiter (Planet) -- Observations, Uranus (Planet) -- Observations, Saturn (Planet) -- Observations, General interest, News, opinion and commentary
Abstract

The spacecraft's farseeing eye once again sets its gaze on Jupiter, Saturn, Uranus and Neptune. You don't need a weatherman to know which way the wind blows on Jupiter. All [...]

Published
2021

23. Numerous polar storms on Saturn analyzed by the UPV/EHU's Planetary Sciences Group

Subjects
Astronomers -- Research, Saturn (Planet) -- Observations, Polar vortex -- Research, Telescopes, Scientists, Storms, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Byline: Staff Writers Barcelona, Spain (SPX) Oct 30, 2019, 2019 Sanchez-Lavega's work appears under the title 'A complex storm system in Saturn's north polar atmosphere in 2018', and was produced [...]

Published
2019

24. Collecting Mars samples

Subjects
Clocks and watches -- Usage, Dust storms -- Natural history -- United States, Mars (Planet) -- Natural history, Planetary rings -- Observations, Astronauts -- Equipment and supplies, Saturn (Planet) -- Observations, Wrist watches -- Usage, Astronomy
Abstract

Q | PERSEVERANCE WILL COLLECT SAMPLES IN SMALL METAL TUBES THAT IT WILL LEAVE ON THE SURFACE OF MARS FOR FUTURE TRANSPORT TO EARTH. ISN'T THERE THE RISK OF THE [...]

Published
2021

25. Small particles dominate Saturn's Phoebe ring to surprisingly large distances

Author

Hamilton, Douglas P., Skrutskie, Michael F., Verbiscer, Anne J., and Masci, Frank J.

Subjects
Saturn (Planet) -- Observations, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Saturn's faint outermost ring, discovered in 2009 (ref. 1), is probably formed by particles ejected from the distant moon Phoebe (2,3). The ring was detected (1) between distances of 128 and 207 Saturn radii ([R.sub.S] = 60,330 kilometres) from the planet, with a full vertical extent of 40 [R.sub.S], making it well over ten times larger than Saturn's hitherto largest known ring, the E ring. The total radial extent of the Phoebe ring could not, however, be determined at that time, nor could particle sizes be significantly constrained. Here we report infrared imaging of the entire ring, which extends from 100 [R.sub.S] out to a surprisingly distant 270 [R.sub.S]. We model the orbital dynamics of ring particles launched from Phoebe, and construct theoretical power-law profiles of the particle size distribution. We find that very steep profiles fit the data best, and that elevated grain temperatures, arising because of the radiative inefficiency of the smallest grains, probably contribute to the steepness. By converting our constraint on particle sizes into a form that is independent of the uncertain size distribution, we determine that particles with radii greater than ten centimetres, whose orbits do not decay appreciably inward over 4.5 billion years, contribute at most about ten per cent to the cross-sectional area of the ring's dusty component., In the course of mapping the entire sky, NASA's WISE spacecraft (4) observed Saturn's outer Phoebe ring at a wavelength of 22 µm in June 2010 (Fig. 1). The ring [...]

Published
2015

26. Saturn's fast spin determined from its gravitational field and oblateness

Author

Helled, Ravit, Galanti, Eli, and Kaspi, Yohai

Subjects
Gravity -- Observations, Rotational motion -- Observations, Saturn (Planet) -- Observations, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

The alignment of Saturn's magnetic pole with its rotation axis precludes the use of magnetic field measurements to determine its rotation period (1). The period was previously determined from radio measurements by the Voyager spacecraft to be 10 h 39 min 22.4 s (ref. 2). When the Cassini spacecraft measured a period of 10 h 47 min 6 s, which was additionally found to change between sequential measurements (3,4,5), it became clear that the radio period could not be used to determine the bulk planetary rotation period. Estimates based upon Saturn's measured wind fields have increased the uncertainty even more, giving numbers smaller than the Voyager rotation period, and at present Saturn's rotation period is thought to be between 10 h 32 min and 10 h 47 min, which is unsatisfactory for such a fundamental property. Here we report a period of 10 h 32 min 45 s ± 46 s, based upon an optimization approach using Saturn's measured gravitational field and limits on the observed shape and possible internal density profiles. Moreover, even when solely using the constraints from its gravitational field, the rotation period can be inferred with a precision of several minutes. To validate our method, we applied the same procedure to Jupiter and correctly recovered its well-known rotation period., Previous theoretical attempts to infer Saturn's rotation period have relied on wind observations derived from cloud tracking at the observed cloud level (6). One theoretical approach was based on minimizing [...]

Published
2015

27. When Saturn Shakes, a Ring Dances

Author

Andrews, Robin George

Subjects
Planetary rings -- Observations -- Structure, Saturn (Planet) -- Observations, General interest, News, opinion and commentary
Abstract

Convulsions in the planet's interior are picked up in the region known as the C ring, and help scientists understand what lies within. Saturn's icy rings are not just aesthetically [...]

Published
2021

28. Jupiter And Saturn To Unite In Night Sky

Subjects
Jupiter (Planet) -- Observations, Saturn (Planet) -- Observations, General interest
Abstract

To listen to this broadcast, click here: http://www.npr.org/templates/transcript/transcript.php?storyId=948315470 HOST: LULU GARCIA-NAVARRO LULU GARCIA-NAVARRO: A cosmic kiss, a celestial celebration, a rare heavenly happening will light up the skies this Monday [...]

Published
2020

29. Jupiter And Saturn Will Be Together Again For The Holidays

Subjects
Jupiter (Planet) -- Observations, Saturn (Planet) -- Observations, General interest
Abstract

To listen to this broadcast, click here: http://www.npr.org/templates/transcript/transcript.php?storyId=944560103 BYLINE: COLIN DWYER HOST: MARY LOUISE KELLY MARY LOUISE KELLY: If you look up at the night sky these days, you may [...]

Published
2020

30. University of Hawaii team unravels origin, chemical makeup of Titan's dunes

Subjects
Saturn (Planet) -- Observations, Moon -- Observations, Remote sensing, Solar System, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry, University of Hawai'i -- Research
Abstract

Byline: Staff Writers Manoa HI (SPX) Oct 21, 2019, 2019 A team led by a University of Hawaii at Manoa chemistry professor and researcher has been able to provide answers [...]

Published
2019

31. Saturn surpasses Jupiter after the discovery of 20 new moons

Subjects
Saturn (Planet) -- Observations, Moon -- Observations, Orbits (Astrophysics), Astronomy, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Byline: Staff Writers Washington DC (SPX) Oct 08, 2019, 2019 Move over Jupiter; Saturn is the new moon king. A team led by Carnegie's Scott S. Sheppard has found 20 [...]

Published
2019

32. 'Snow-Cannon' Enceladus shines up Saturn's super-reflective moons

Subjects
Saturn (Planet) -- Observations, Reflectors (Lighting) -- Research, Enceladus (Satellite) -- Observations -- Natural history, Coatings, Astronomy, Water, Spacecraft, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Byline: Staff Writers Geneva, Switzerland (SPX) Sep 19, 2019, 2019 Radar observations of Saturn's moons, Mimas, Enceladus and Tethys, show that Enceladus is acting as a 'snow-cannon,' coating itself and [...]

Published
2019

33. Saturn's Rings Shine in New Hubble Portrait

Subjects
Hubble Space Telescope (Artificial satellite) -- Observations, Saturn (Planet) -- Observations, Telescopes -- Observations, Astronomy -- Observations, Planetary rings -- Observations, Sound recordings, Solar System, Spacecraft, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Byline: Staff Writers Baltimore MD (SPX) Sep 13, 2019, 2019 Anyone who has ever peered at Saturn through a small telescope is immediately enticed by its elegant rings, which make [...]

Published
2019

34. Dragonfly Mission to Study Titan for Origins, Signs of Life

Subjects
United States. National Aeronautics and Space Administration -- Research, Saturn (Planet) -- Observations, Origin of life -- Research, Titan (Satellite) -- Observations, Scientists, Professional associations, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Byline: Staff Writers Tucson AZ (SPX) Jul 02, 2019, 2019 NASA has announced funding for the Dragonfly mission, featuring a drone-like rotorcraft lander that would explore the prebiotic chemistry and [...]

Published
2019

35. Cassini reveals new sculpting in Saturn rings

Subjects
United States. National Aeronautics and Space Administration -- Research -- Equipment and supplies, Saturn (Planet) -- Observations, Spacecraft -- Observations, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Byline: Staff Writers Pasadena CA (SPX) Jun 17, 2019, 2019 As NASA's Cassini dove close to Saturn in its final year, the spacecraft provided intricate detail on the workings of [...]

Published
2019

36. Researchers find ice feature on Saturn's giant moon

Subjects
Cassini (Space probe), Saturn (Planet) -- Observations, Satellites (Astronomical bodies) -- Observations, Space probes, Astronomy, Methane, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry, The University of Arizona -- Research
Abstract

Byline: Staff Writers Tucson AZ (SPX) May 01, 2019, 2019 Rain, seas and a surface of eroding organic material can be found both on Earth and on Saturn's largest moon, [...]

Published
2019

37. New surprises from Jupiter and Saturn

Subjects
Saturn (Planet) -- Observations, Jupiter (Planet) -- Observations, Unmanned spacecraft, Conferences and conventions, Planets, Spacecraft, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Byline: Staff Writers Washington DC (SPX) Mar 11, 2019, 2019 The latest data sent back by the Juno and Cassini spacecraft from giant gas planets Jupiter and Saturn have challenged [...]

Published
2019

38. Scientist sheds light on Titan's mysterious nitrogen atmosphere

Subjects
Moon -- Observations, Planetary atmospheres -- Research, Saturn (Planet) -- Observations, Scientists, Research scientists, Research institutes, Solar System, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry, Southwest Research Institute -- Research
Abstract

Byline: Staff WritersSan Antonio TX (SPX) Jan 24, 2019, 2019 A new Southwest Research Institute study tackles one of the greatest mysteries about Titan, one of Saturn's moons: the origin [...]

Published
2019

39. Waves in Saturn's rings give precise measurement of planet's rotation rate

Subjects
Cassini (Space probe) -- Observations, Astronomical rotation -- Measurement, Planetary rings -- Research, Saturn (Planet) -- Observations, Saturn probes -- Observations, Wave motion -- Research, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Byline: Staff Writers Santa Cruz CA (SPX) Jan 21, 2019, 2019 Saturn's distinctive rings were observed in unprecedented detail by NASA's Cassini spacecraft, and scientists have now used those observations [...]

Published
2019

40. Scientists Finally Know What Time It Is on Saturn

Subjects
United States. National Aeronautics and Space Administration -- Research, Saturn (Planet) -- Observations, Magnetic fields -- Research, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Byline: Staff Writers Washington DC (SPX) Jan 21, 2019, 2019 Using new data from NASA's Cassini spacecraft, researchers believe they have solved a longstanding mystery of solar system science: the [...]

Published
2019

41. Saturn at its best: Saturn is closest in May and June, with its rings tipped wide open

Author

MacRobert, Alan

Subjects
Observational astronomy, Jupiter (Planet) -- Observations, Planetary rings -- Observations, Saturn (Planet) -- Observations, Astronomy
Abstract

As Jupiter sinks westward through the hours of the night and through the weeks of late spring, Saturn comes up in the southeast to lure your telescope away. Saturn reaches [...]

Published
2015

42. NASA Research Reveals Saturn is Losing Its Rings at 'Worst-Case-Scenario' Rate

Author

Steigerwald, Bill and Jones, Nancy

Subjects
United States. National Aeronautics and Space Administration -- Research, Saturn (Planet) -- Observations, Aerospace and defense industries, Astronomy, High technology industry, Telecommunications industry
Abstract

Byline: Bill Steigerwald and Nancy Jones for GSFC NewsGreenbelt MD (SPX) Dec 18, 2018, 2018 New NASA research confirms that Saturn is losing its iconic rings at the maximum rate [...]

Published
2018

43. Saturns unite! Catch both the planet and the nebula

Author

Chaple, Glenn

Subjects
Planetary nebulae -- Observations, Saturn (Planet) -- Observations, Astronomy
Abstract

This month, we voyage to a pair of Saturns--first the planet, then its namesake nebula. The planet currently resides in the constellation Capricornus, while the Saturn Nebula is conveniently located [...]

Published
2021

45. How to see and photograph the great conjunction of 2020

Author

Semeniuk, Ivan

Subjects
Jupiter (Planet) -- Observations, Binoculars -- Usage, Saturn (Planet) -- Observations, Alignments (Astronomy) -- Observations, General interest, News, opinion and commentary
Abstract

Byline: IVAN SEMENIUK, Staff Lead Skywatchers are gearing up Monday night for an unusually close alignment of Jupiter and Saturn, the solar system's two largest planets. The rare spectacle, which [...]

Published
2020

46. This Solstice, Solace for the Darkness

Author

Overbye, Dennis

Subjects
Jupiter (Planet) -- Observations, Saturn (Planet) -- Observations, Market trend/market analysis, General interest, News, opinion and commentary
Abstract

A rare conjunction of planets serves as a reminder that there is more to the universe than just ourselves. We have now arrived at the longest, darkest night of the [...]

Published
2020

47. Jupiter and Saturn Head for Their Closest Visible Alignment in Centuries

Author

Levenson, Michael

Subjects
Saturn (Planet) -- Observations, Jupiter (Planet) -- Observations, Alignments (Astronomy) -- Observations, General interest, News, opinion and commentary
Abstract

On Dec. 21, Jupiter and Saturn will appear to be no more than a dime's width apart in the night sky. The last time that could be seen was in [...]

Published
2020

49. Does meth flow ane on titan?: Scientists are eager to prove that the meandering river valleys and braided streambeds seen on Saturn's largest moon carry liquid methane to its vast lakes

Author

Zimmerman, Robert

Subjects
Huygens (Space probe) -- Usage, Methane -- Discovery and exploration, Meandering rivers -- Observations, Titan (Satellite) -- Composition -- Observations, Saturn (Planet) -- Observations, Astronomy
Abstract

Nine years ago, Europe's Huygens probe dropped through the atmosphere of Saturn's moon Titan and landed on the surface. Planetary scientists reacted with unbridled joy to the mission's success. 'I [...]

Published
2014

50. Saturn's Northern hemisphere Ribbon: simulations and comparison with the meandering gulf stream

Author

Sayanagi, Kunio M., Morales-Juberias, Raul, and Ingersoll, Andrew P.

Subjects
Saturn (Planet) -- Observations, Arctic Oscillation -- Research, Meandering rivers -- Research, Earth sciences, Science and technology
Abstract

Voyager observations of Saturn in 1980-81 discovered a wavy feature engirdling the planet at 47[degrees]N planetographic latitude. Its latitude coincides with that of an eastward jet stream, which is the second fastest on Saturn after the equatorial jet. The 47[degrees]N jet's wavy morphology is unique among the known atmospheric jets on the gas giant planets. Since the Voyagers, it has been seen in every high-resolution image of this latitude for over 25 years and has been termed the Ribbon. The Ribbon has been interpreted as a dynamic instability in the jet stream. This study tests this interpretation and uses forward modeling to explore the observed zonal wind profile's stability properties. Unforced, initial-value numerical experiments are performed to examine the nonlinear evolution of the jet stream. Parameter variations show that an instability occurs when the 47[degrees]N jet causes reversals in the potential vorticity (PV) gradient, which constitutes a violation of the Charney-Stern stability criterion. After the initial instability development, the simulations demonstrate that the instability's amplitude nonlinearly saturates to a constant when the eddy generation by the instability is balanced by the destruction of the eddies. When the instability saturates, the zonal wind profile approaches neutral stability according to Arnol'd's second criterion, and the jet's path meanders in a Ribbon-like manner. It is demonstrated that the meandering of the 47[degrees]N jet occurs over a range of tropospheric static stability and background wind speed. The results here show that a nonlinearly saturated shear instability in the 47[degrees]N jet is a viable mechanism to produce the Ribbon morphology. Observations do not yet have the temporal coverage to confirm the creation and destruction of eddies, but these simulations predict that this is actively occurring in the Ribbon region. Similarities exist between the behaviors found in this model and the dynamics of PV fronts studied in the context of meandering western boundary currents in Earth's oceans. In addition, the simulations capture the nonlinear aspects of a new feature discovered by the Cassini Visual and Infrared Mapping Spectrometer (VIMS), the String of Pearls, which resides in the equatorward tip of the 47[degrees]N jet. The Explicit Planetary Isentropic Coordinate (EPIC) model is used herein. DOI: 10.1175/2010JAS3315.1

Published
2010

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