Comet C/2012 S1 was discovered in September 2012 by Russian astronomers Vitali Nevski and Artyom Novichonok using data from the International Scientific Optical Network (ISON). For that reason, it is also known as Comet ISON. This comet is on a close encounter with the Sun on November 28, 2013 (Thanksgiving day in the U.S.), when it will pass at a distance of only 2.7 solar radii from the center of the Sun. Since Comet ISON was discovered so far out, beyond the orbit of Jupiter, and will pass so close to the Sun, many think that this could turn out to be a major comet. A number of solar missions, including SOHO, are planning an observing campaign to observe the comet as it passes by the Sun.

SOHO's LASCO C2 and C3 coronagraphs are expected to have a view of the comet as it passes through their fields-of-view, as shown below. From SOHO's viewpoint the comet enters from the lower right early on November 27 and exits towards the top near the end of November 30.

The trajectory information on this page are based on preliminary estimates of Comet ISON's orbit. As more observations of the comet are collected, these orbital estimates will be improved over time.

 See the webside for more details:   http://sohowww.nascom.nasa.gov/hotshots/index.html/（SY）