Old Project Avalon Forum (ARCHIVE) - View Single Post

judykott · 02-01-2009, 11:01 PM

The internal angles of a regular hexagon (one where all sides and all angles are equal) are all 120° and the hexagon has 720 degrees T. It has 6 rotational symmetries and 6 reflection symmetries, making up the dihedral group D6. The longest diagonals of a regular hexagon, connecting diametrically opposite vertices, are twice its sides in length. Like squares and equilateral triangles, regular hexagons fit together without any gaps to tile the plane (three hexagons meeting at every vertex), and so are useful for constructing tessellations. The cells of a beehive honeycomb are hexagonal for this reason and because the shape makes efficient use of space and building materials. The Voronoi diagram of a regular triangular lattice is the honeycomb tessellation of hexagons.

A persisting hexagonal wave pattern around the Saturn's north polar vortex in the atmosphere at about 78°N was first noted in the Voyager images.[25][26] Unlike the north pole, HST imaging of the south polar region indicates the presence of a jet stream, but no strong polar vortex nor any hexagonal standing wave.[27] However, NASA reported in November 2006 that the Cassini spacecraft observed a 'hurricane-like' storm locked to the south pole that had a clearly defined eyewall.[28] This observation is particularly notable because eyewall clouds had not previously been seen on any planet other than Earth (including a failure to observe an eyewall in the Great Red Spot of Jupiter by the Galileo spacecraft).[29]

The straight sides of the northern polar hexagon are each about 13 800 km long. The entire structure rotates with a period of 10h 39 m 24s, the same period as that of the planet's radio emissions, which is assumed to be equal to the period of rotation of Saturn's interior. The hexagonal feature does not shift in longitude like the other clouds in the visible atmosphere.

The pattern's origin is a matter of much speculation. Most astronomers seem to think some sort of standing-wave pattern in the atmosphere; but the hexagon might be a novel sort of aurora. Polygon shapes have been replicated in spinning buckets of fluid in a laboratory.[30]

Magnetosphere
Saturn has an intrinsic magnetic field that has a simple, symmetric shape—a magnetic dipole. Its strength at the equator—0.2 gau

http://en.wikipedia.org/wiki/File:Sa...le_feature.jpg

A bizarre six-sided feature encircling the north pole of en:Saturn near 78 degrees north latitude has been spied by the visual and infrared mapping spectrometer on NASA's Cassini spacecraft. This image is one of the first clear images ever taken of the north polar region as seen from a unique polar perspective.

Originally discovered and last observed by a spacecraft during NASA's Voyager flybys of the early 1980's, the new views of this polar en:hexagon taken in late 2006 prove that this is an unusually long-lived feature on Saturn.

This image is the first to capture the entire feature and north polar region in one shot, and is also the first polar view using Saturn's thermal glow at 5 en:microns (seven times the wavelength visible to the en:human eye) as the light source. This allows the pole to be revealed during the nighttime conditions presently underway during north polar winter. Previous images from Voyager and from ground-based en:telescopes suffered from poor viewing perspectives, which placed the feature and the north pole at the extreme northern limb (edge) of the planet.

To see the deep atmosphere at night, the en:infrared instrument images the thermal glow radiating from Saturn's depths. Clouds at depths about 75 kilometers (47 miles) lower than the clouds seen at visible wavelengths block this light, appearing dark in silhouette. To show clouds as features that are bright or white rather than dark, the original image has been contrast reversed to produce the image shown here. The nested set of alternating white and dark hexagons indicates that the hexagonal complex extends deep into the atmosphere, at least down to the 3-Earth-atmosphere pressure level, some 75 kilometers (47 miles) underneath the clouds seen by Voyager. Multiple images acquired over a 12-day period between en:October 30 and en:November 11, en:2006, show that the feature is nearly stationary, and likely is an unusually strong pole-encircling planetary wave that extends deep into the atmosphere.

This image was acquired on en:October 29, 2006, from an average distance of 902,000 kilometers (560,400 miles) above the cloud tops of Saturn.

The Cassini-Huygens mission is a cooperative project of NASA, the en:European Space Agency and the en:Italian Space Agency. The en:Jet Propulsion Laboratory, a division of the en:California Institute of Technology in en:Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Visual and Infrared Mapping Spectrometer team is based at the en:University of Arizona, where this image was produced.

For more information about the Cassini-Huygens mission visit saturn.jpl.nasa.gov. The visual and infrared mapping spectrometer team homepage is at wwwvims.lpl.arizona.edu.

Credit: NASA/JPL/University of Arizona"

02-01-2009, 11:01 PM	#3
judykott Avalon Senior Member Join Date: Oct 2008 Location: Calgary, Canada Posts: 711	Re: cosmic anomilies and hexagons The internal angles of a regular hexagon (one where all sides and all angles are equal) are all 120° and the hexagon has 720 degrees T. It has 6 rotational symmetries and 6 reflection symmetries, making up the dihedral group D6. The longest diagonals of a regular hexagon, connecting diametrically opposite vertices, are twice its sides in length. Like squares and equilateral triangles, regular hexagons fit together without any gaps to tile the plane (three hexagons meeting at every vertex), and so are useful for constructing tessellations. The cells of a beehive honeycomb are hexagonal for this reason and because the shape makes efficient use of space and building materials. The Voronoi diagram of a regular triangular lattice is the honeycomb tessellation of hexagons. A persisting hexagonal wave pattern around the Saturn's north polar vortex in the atmosphere at about 78°N was first noted in the Voyager images.[25][26] Unlike the north pole, HST imaging of the south polar region indicates the presence of a jet stream, but no strong polar vortex nor any hexagonal standing wave.[27] However, NASA reported in November 2006 that the Cassini spacecraft observed a 'hurricane-like' storm locked to the south pole that had a clearly defined eyewall.[28] This observation is particularly notable because eyewall clouds had not previously been seen on any planet other than Earth (including a failure to observe an eyewall in the Great Red Spot of Jupiter by the Galileo spacecraft).[29] The straight sides of the northern polar hexagon are each about 13 800 km long. The entire structure rotates with a period of 10h 39 m 24s, the same period as that of the planet's radio emissions, which is assumed to be equal to the period of rotation of Saturn's interior. The hexagonal feature does not shift in longitude like the other clouds in the visible atmosphere. The pattern's origin is a matter of much speculation. Most astronomers seem to think some sort of standing-wave pattern in the atmosphere; but the hexagon might be a novel sort of aurora. Polygon shapes have been replicated in spinning buckets of fluid in a laboratory.[30] Magnetosphere Saturn has an intrinsic magnetic field that has a simple, symmetric shape—a magnetic dipole. Its strength at the equator—0.2 gau http://en.wikipedia.org/wiki/File:Sa...le_feature.jpg A bizarre six-sided feature encircling the north pole of en:Saturn near 78 degrees north latitude has been spied by the visual and infrared mapping spectrometer on NASA's Cassini spacecraft. This image is one of the first clear images ever taken of the north polar region as seen from a unique polar perspective. Originally discovered and last observed by a spacecraft during NASA's Voyager flybys of the early 1980's, the new views of this polar en:hexagon taken in late 2006 prove that this is an unusually long-lived feature on Saturn. This image is the first to capture the entire feature and north polar region in one shot, and is also the first polar view using Saturn's thermal glow at 5 en:microns (seven times the wavelength visible to the en:human eye) as the light source. This allows the pole to be revealed during the nighttime conditions presently underway during north polar winter. Previous images from Voyager and from ground-based en:telescopes suffered from poor viewing perspectives, which placed the feature and the north pole at the extreme northern limb (edge) of the planet. To see the deep atmosphere at night, the en:infrared instrument images the thermal glow radiating from Saturn's depths. Clouds at depths about 75 kilometers (47 miles) lower than the clouds seen at visible wavelengths block this light, appearing dark in silhouette. To show clouds as features that are bright or white rather than dark, the original image has been contrast reversed to produce the image shown here. The nested set of alternating white and dark hexagons indicates that the hexagonal complex extends deep into the atmosphere, at least down to the 3-Earth-atmosphere pressure level, some 75 kilometers (47 miles) underneath the clouds seen by Voyager. Multiple images acquired over a 12-day period between en:October 30 and en:November 11, en:2006, show that the feature is nearly stationary, and likely is an unusually strong pole-encircling planetary wave that extends deep into the atmosphere. This image was acquired on en:October 29, 2006, from an average distance of 902,000 kilometers (560,400 miles) above the cloud tops of Saturn. The Cassini-Huygens mission is a cooperative project of NASA, the en:European Space Agency and the en:Italian Space Agency. The en:Jet Propulsion Laboratory, a division of the en:California Institute of Technology in en:Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Visual and Infrared Mapping Spectrometer team is based at the en:University of Arizona, where this image was produced. For more information about the Cassini-Huygens mission visit saturn.jpl.nasa.gov. The visual and infrared mapping spectrometer team homepage is at wwwvims.lpl.arizona.edu. Credit: NASA/JPL/University of Arizona"