Pale Blue Dot - NASA

PIA00452: Solar System Portrait - Earth as 'Pale Blue Dot'

Original Caption Released with Image: This narrow-angle color image of the Earth, dubbed 'Pale Blue Dot', is a part of the first ever 'portrait' of the solar system taken by Voyager 1. The spacecraft acquired a total of 60 frames for a mosaic of the solar system from a distance of more than 4 billion miles from Earth and about 32 degrees above the ecliptic. From Voyager's great distance Earth is a mere point of light, less than the size of a picture element even in the narrow-angle camera. Earth was a crescent only 0.12 pixel in size. Coincidentally, Earth lies right in the center of one of the scattered light rays resulting from taking the image so close to the sun. This blown-up image of the Earth was taken through three color filters -- violet, blue and green -- and recombined to produce the color image. The background features in the image are artifacts resulting from the magnification. Image Credit: NASA/JPL Image Addition Date: 1996-09-12 이 사진은 칼 세이건의 의도에서 촬영된 것이었다. 세이건은 자신의 저서에서, "지구는 광활한 우주에 떠 있는 보잘것없는 존재에 불과함을 사람들에게 가르쳐 주고 싶었다" 라고 밝혔다. 이런 의도로 그는 보이저 1호의 카메라를 지구 쪽으로 돌릴 것을 지시했다. 많은 반대가 있었으나, 결국 지구를 포함한 6개 행성들을 찍을 수 있었고 이 사진들은 '가족 사진'으로 이름붙여졌다. 다만 수성은 너무 밝은 태양빛에 묻혀 버렸고, 화성은 카메라에 반사된 태양광 때문에 촬영할 수 없었다. 지구 사진은 이들 중 하나이다. ===============================================================================    In Saturn's Shadow10.11.06 With giant Saturn hanging in the blackness and sheltering Cassini from the sun's blinding glare, the spacecraft viewed the rings as never before, revealing previously unknown faint rings and even glimpsing its home world. This marvelous panoramic view was created by combining a total of 165 images taken by the Cassini wide-angle camera over nearly three hours on Sept. 15, 2006. The full mosaic consists of three rows of nine wide-angle camera footprints; only a portion of the full mosaic is shown here. Color in the view was created by digitally compositing ultraviolet, infrared and clear filter images and was then adjusted to resemble natural color.  The mosaic images were acquired as the spacecraft drifted in the darkness of Saturn's shadow for about 12 hours, allowing a multitude of unique observations of the microscopic particles that compose Saturn's faint rings. Ring structures containing these tiny particles brighten substantially at high phase angles: i.e., viewing angles where the sun is almost directly behind the objects being imaged. During this period of observation Cassini detected two new faint rings: one coincident with the shared orbit of the moons Janus and Epimetheus, and another coincident with Pallene's orbit. (See http://www.nasa.gov/mission_pages/cassini/multimedia/pia08322.html and http://www.nasa.gov/mission_pages/cassini/multimedia/pia08328.html for more on the two new rings.) The narrowly confined G ring is easily seen here, outside the bright main rings. Encircling the entire system is the much more extended E ring. The icy plumes of Enceladus, whose eruptions supply the E ring particles, betray the moon's position in the E ring's left-side edge.  Interior to the G ring and above the brighter main rings is the pale dot of Earth. Cassini views its point of origin from over a billion kilometers (and close to a billion miles) away in the icy depths of the outer solar system. See PIA08324 for a similar view of Earth taken during this observation. Small grains are pushed about by sunlight and electromagnetic forces. Hence their distribution tells much about the local space environment. A second version of the mosaic view is presented here in which the color contrast is greatly exaggerated. In such views, imaging scientists have noticed color variations across the diffuse rings that imply active processes sort the particles in the ring according to their sizes. Looking at the E ring in this color-exaggerated view, the distribution of color across and along the ring appears to be different between the right side and the left. Scientists are not sure yet how to explain these differences, though the difference in phase angle between right and left may be part of the explanation. The phase angle is about 179 degrees on Saturn. The main rings are overexposed in a few places. This view looks toward the unlit side of the rings from about 15 degrees above the ringplane. Cassini was approximately 2.2 million kilometers (1.3 million miles) from Saturn when the images in this mosaic were taken. Image scale on Saturn is about 260 kilometers (162 miles) per pixel. The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. 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 and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org. Image credit: NASA/JPL/Space Science Institute