File:PIA21628 - B Ring fine structure in color.jpg
原始檔案 (1,959 × 1,000 像素,檔案大小:1.78 MB,MIME 類型:image/jpeg)
摘要
描述PIA21628 - B Ring fine structure in color.jpg |
English: Uploader's notes: the original NASA image has been modified by removal of artifacts and converting from TIFF to JPG format. Original caption released with image: These are the highest-resolution color images of any part of Saturn's rings, to date, showing a portion of the inner-central part of the planet's B Ring. The view is a mosaic of two images that show a region that lies between 61,300 and 65,600 miles (98,600 and 105,500 kilometers) from Saturn's center. The first image (Figure A) is a natural color composite, created using images taken with red, green and blue spectral filters. The pale tan color is generally not perceptible with the naked eye in telescope views, especially given that Saturn has a similar hue. The material responsible for bestowing this color on the rings -- which are mostly water ice and would otherwise appear white -- is a matter of intense debate among ring scientists that will hopefully be settled by new in-situ observations before the end of Cassini's mission. The different ringlets seen here are part of what is called the "irregular structure" of the B ring. Cassini radio occultations of the rings have shown that these features have extremely sharp boundaries on even smaller scales (radially, or along the direction outward from Saturn) than the camera can resolve here. Closer to Saturn, the irregular structures become fuzzier and more rounded, less opaque, and their color contrast diminishes. The narrow ringlets in the middle of this scene are each about 25 miles (40 kilometers) wide, and the broader bands at right are about 200 to 300 miles (300 to 500 kilometers) across. It remains unclear exactly what causes the variable brightness of these ringlets and bands -- the basic brightness of the ring particles themselves, shadowing on their surfaces, their absolute abundance, and how densely the particles are packed, may all play a role. The second image (Figure B) is a color-enhanced version. Blue colors represent areas where the spectrum at visible wavelengths is less reddish (meaning the spectrum is flatter toward red wavelengths), while red colors represent areas that are spectrally redder (meaning the spectrum has a steeper spectrum toward red wavelengths). Observations from the Voyager mission and Cassini's visual and infrared mapping spectrometer previously showed these color variations at lower resolution, but it was not known that such well-defined color contrasts would be this sharply defined down to the scale (radial scale) of a couple of miles or kilometers, as seen here. Analysis of additional images from this observation, taken using infrared spectral filters sensitive to absorption of light by water ice, indicates that the areas that appear more visibly reddish in the color-enhanced version are also richer in water ice. The third image (Figure C) is a composite of the "true" and "enhanced" color images for easy comparison. This image was taken on July 6, 2017, with the Cassini spacecraft narrow-angle camera. The image was acquired on the sunlit side of the rings from a distance of 47,000 miles (76,000 kilometers) away from the area pictured. The image scale is about 2 miles (3 kilometers) per pixel. The phase angle, or sun-ring-spacecraft angle, is 90 degrees. The Cassini Solstice Mission is a joint United States and European endeavor. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The imaging team consists of scientists from the US, England, France, and Germany. The imaging operations center and team lead (Dr. C. Porco) are based at the Space Science Institute in Boulder, Colo. For more information about the Cassini Solstice Mission visit http://ciclops.org, http://www.nasa.gov/cassini and http://saturn.jpl.nasa.gov. |
日期 | 6 July 2017 (published 7 September 2017) |
來源 |
https://photojournal.jpl.nasa.gov/catalog/PIA21628 or http://ciclops.org/view/8613/Colorful-Structure-at-Fine-Scales |
作者 | NASA / Jet Propulsion Lab-Caltech / Space Science Institute |
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Public domainPublic domainfalsefalse |
本作品由NASA創作,屬於公有領域。根據NASA的版權政策:“NASA的創作除非另有聲明否則不受版權保護。”(參見:Template:PD-USGov/zh,NASA版權政策或JPL圖像使用政策) | ||
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目前 | 2017年9月10日 (日) 00:28 | 1,959 × 1,000(1.78 MB) | WolfmanSF | User created page with UploadWizard |
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寬度 | 1,959 px |
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高度 | 1,000 px |
每像素位元 |
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壓縮方式 | 未壓縮 |
像素合成 | RGB |
方位 | 標準 |
像素數量 | 3 |
水平解析度 | 72 dpi |
垂直解析度 | 72 dpi |
資料排列 | 矮胖格式 |
使用軟體 | Adobe Photoshop Elements 15.0 (Windows) |
檔案修改日期時間 | 2017年9月9日 (六) 17:12 |
Exif 版本 | 2.21 |
色彩空間 | 顏色未校準 |
數位化的日期時間 | 2017年7月11日 (二) 02:24 |
詮釋資料最後修改日期 | 2017年9月9日 (六) 10:12 |
原始文件唯一識別碼 | xmp.did:ee5ec907-83c8-4bab-a978-f4b1c762973e |