Earth-like weather encounters 'throwing jet streams off course on Jupiter'Mar 14, 11:50 am
Washington, Mar 14 (ANI): Scientists have for the first time identified direct wave motion in one of Jupiter's jet streams.New movies of Jupiter are the first to catch an invisible wave shaking up one of the giant planet's jet streams, an interaction that also takes place in Earth's atmosphere and influences the weather. The movies, made from images taken by NASA's Cassini spacecraft when it flew by Jupiter in 2000, are part of an in-depth study conducted by a team of scientists and amateur astronomers led by Amy Simon-Miller at NASA's Goddard Space Flight Center in Greenbelt, Md."This is the first time anyone has actually seen direct wave motion in one of Jupiter's jet streams,"' says Simon-Miller, the paper's lead author. "'And by comparing this type of interaction in Earth's atmosphere to what happens on a planet as radically different as Jupiter, we can learn a lot about both planets."'Like Earth, Jupiter has several fast-moving jet streams that circle the globe. Earth's strongest and best known jet streams are those near the north and south poles; as these winds blow west to east, they take the scenic route, wandering north and south. What sets these jet streams on their meandering paths and sometimes makes them blast Florida and other warm places with frigid air are their encounters with slow-moving waves in Earth's atmosphere, called Rossby waves. n contrast, Jupiter's jet streams "'have always appeared to be straight and narrow,"' said co-author John Rogers, who is the Jupiter Section Director of the British Astronomical Association, London, U.K., and one of the amateur astronomers involved in this study.Rossby waves were identified on Jupiter about 20 years ago, in the northern hemisphere. Even so, the expected meandering winds could not be traced directly, and no evidence of them had been found in the southern hemisphere, which puzzled planetary scientists.To get a more complete view, the team analyzed images taken by NASA's Voyager spacecraft, NASA's Hubble Space Telescope, and Cassini, as well as a decade's worth of observations made by amateur astronomers and compiled by the JUPOS project.The movies zoom in on a single jet stream in Jupiter's southern hemisphere. A line of small, dark, V-shaped "'chevrons"' has formed along one edge of the jet stream and zips along west to east with the wind. Later, the well-ordered line starts to ripple, with each chevron moving up and down (north and south) in turn. And for the first time, it's clear that Jupiter's jet streams, like Earth's, wander off course."'That's the signature of the Rossby wave," said David Choi, the postdoctoral fellow at NASA Goddard who strung together about a hundred Cassini images to make each time-lapse movie. "The chevrons in the fast-moving jet stream interact with the slower-moving Rossby wave, and that's when we see the chevrons oscillate."The team's analysis also reveals that the chevrons are tied to a different type of wave in Jupiter's atmosphere, called a gravity inertia wave. Earth also has gravity inertia waves, and under proper conditions, these can be seen in repeating cloud patterns."A planet's atmosphere is a lot like the string of an instrument," said co-author Michael D. Allison of the NASA Goddard Institute for Space Studies in New York. "If you pluck the string, it can resonate at different frequencies, which we hear as different notes. In the same way, an atmosphere can resonate with different modes, which is why we find different kinds of waves."Characterizing these waves should offer important clues to the layering of the deep atmosphere of Jupiter, which has so far been inaccessible to remote sensing, Allison asserted. Crucial to the study was the complementary information that the team was able to retrieve from the detailed spacecraft images and the more complete visual record provided by amateur astronomers. The team also relied on images that amateur astronomers had been gathering of a large, transient storm called the South Equatorial Disturbance. Analysis of these images revealed the dynamics of this storm and its impact on the chevrons. he team now thinks this storm, together with the Great Red Spot, accounts for many of the differences noted between the jet streams and Rossby waves on the two sides of Jupiter's equator. "We are just starting to investigate the long-term behavior of this alien atmosphere," said co-author Gianluigi Adamoli, an amateur astronomer in Italy. "Understanding the emerging analogies between Earth and Jupiter, as well as the obviously profound differences, helps us learn fundamentally what an atmosphere is and how it can behave," Adamoli added.The study has been published in Icarus. (ANI)
`Cannibalism` between stars Feb 6, 4:12 pm
Washington D.C, Feb 6 (ANI): Unveiling the turbulent past of our sun, a team of researchers has shown 'cannibalism' between stars.Full Story »
Jupiter's role as Earth's protector challenged Feb 4, 9:55 am
Washington D.C, Feb 4 (ANI): Since 1941, many astronomers have thought of Jupiter as a protective big brother for planet Earth, deflecting asteroids and comets away from the inner Solar System, and now, a new study has challenged its role as the celestial shield.Full Story »
Antarctic fungi survive Martian conditions Jan 29, 12:37 pm
Washington D.C, Jan 29 (ANI): The quest for life on Mars is as tantalizing as ever and now, an experiment conducted on the International Space Station has suggested that fungi and lichens may be able to survive on Mars.Full Story »
Monstrous cloud boomeranging back to Milky Way Jan 29, 10:38 am
Washington D.C, Jan 29 (ANI): A team of researchers has revealed that the old adage "what goes up must come down" is ringing true for an immense cloud of hydrogen gas that is heading towards our galaxy at nearly 700,000 miles per hour.Full Story »
- Volunteer programmers help find mysterious black holes
- Lasagne-like dark `noodle` spotted in Milky Way
- Ninth planet lurking at edge of solar system?
- NASA: First flower ever in outer space blooms
- Universe's most luminous galaxy is 'ripping' itself!
- Mystery in Milkyway: Brightest explosion ever seen!
- Astronomers discover most luminous supernova ever
- Early universe evolution can be perceived from 'Green pea galaxy'
- 'Spiders' spotted on Mars!
- `Massive` galaxy cluster detected after 3.8 billion years of Big Bang
TOP VIDEO STORIES