more at http://scitech.quickfound.net 'This movie from NASA's STEREO spacecraft's Heliospheric Imager shows Comet ISON, Mercury, Comet Encke and Earth over a five-day period from Nov. 20 to Nov. 25, 2013. The sun sits right of the field of view of this camera. Comet ISON, which will round the sun on Nov. 28, is what's known as a sungrazing comet, due to its close approach. A comet's journey through the solar system is perilous and violent. A giant ejection of solar material from the sun could rip its tail off. Before it reaches Mars -- at some 230 million miles away from the sun -- the radiation of the sun begins to boil its water, the first step toward breaking apart. And, if it survives all this, the intense radiation and pressure as it flies near the surface of the sun could destroy it altogether. Even if the comet does not survive, tracking its journey will help scientists understand what the comet is made of, how it reacts to its environment, and what this explains about the origins of the solar system. Closer to the sun, watching how the comet and its tail interact with the vast solar atmosphere can teach scientists more about the sun itself.' Image Credit: NASA/STEREO Public domain film from NASA Goddard Space Flight Center, slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied. Silent. http://creativecommons.org/licenses/by-sa/3.0/ http://en.wikipedia.org/wiki/C/2012_S1 C/2012 S1, also known as Comet ISON or Comet Nevski--Novichonok, is a sungrazing comet discovered on 21 September 2012 by Vitali Nevski (Виталий Невский, Vitebsk, Belarus) and Artyom Novichonok (Артём Новичонок, Kondopoga, Russia). The discovery was made using the 0.4-meter (16 in) reflector of the International Scientific Optical Network (ISON) near Kislovodsk, Russia. Data processing was carried out by automated asteroid-discovery program CoLiTec. Precovery images by the Mount Lemmon Survey from 28 December 2011 and by Pan-STARRS from 28 January 2012 were quickly located. Follow-up observations were made on 22 September by a team from Remanzacco Observatory in Italy using the iTelescope network. The discovery was announced by the Minor Planet Center on 24 September. Observations by Swift in January 2013 suggested that C/2012 S1's nucleus was around 5 kilometers (3 mi) in diameter... Orbit C/2012 S1 will come to perihelion (closest approach to the Sun) on 28 November 2013 at a distance of 0.0124 AU (1,860,000 km; 1,150,000 mi) from the center point of the Sun. Accounting for the solar radius of 695,500 km (432,200 mi), C/2012 S1 will pass approximately 1,165,000 km (724,000 mi) above the Sun's surface. Its trajectory appears to be hyperbolic, which suggests that it is a dynamically new comet coming freshly from the Oort cloud. Near perihelion, a generic heliocentric two-body solution to the orbit suggests that the orbital period is around 400,000 years. But for objects at such high eccentricity, the Sun's barycentric coordinates are more stable than heliocentric coordinates. The orbit of a long-period comet is properly obtained when the osculating orbit is computed at an epoch after leaving the planetary region and is calculated with respect to the center of mass of the Solar System. Using JPL Horizons, the barycentric orbital elements for epoch 1 January 2050 generate a hyperbolic solution. On its closest approach, C/2012 S1 passed about 0.07248 AU (10,843,000 km; 6,737,000 mi) from Mars on 1 October 2013, and it will pass about 0.43 AU (64,000,000 km; 40,000,000 mi) from Earth on 26 December 2013. Shortly after its discovery, similarities between the orbital elements of C/2012 S1 and the Great Comet of 1680 led to speculation that there might be a connection between them. Further observations of ISON, however, showed that the two comets are not related. Earth will pass near the orbit of C/2012 S1 on 14--15 January 2014, well after C/2012 S1 has passed, at which time micron-sized dust particles blown by the Sun's radiation may cause a meteor shower or noctilucent clouds; however, both events are unlikely... http://en.wikipedia.org/wiki/STEREO STEREO (Solar TErrestrial RElations Observatory) is a solar observation mission. Two nearly identical spacecraft were launched in 2006 into orbits around the Sun that cause them to respectively pull farther ahead of and fall gradually behind the Earth. This enables stereoscopic imaging of the Sun and solar phenomena, such as coronal mass ejections... The two STEREO spacecraft were launched at 0052 UTC on October 26, 2006 from Launch Pad 17B at the Cape Canaveral Air Force Station in Florida on a Delta II 7925-10L launcher...

• published: 27 Nov 2013
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