CAPE CANAVERAL, Florida --Comet ISON, which scientist believed had disintegrated on its Thanksgiving Day close encounter with the sun, may have survived.
According to NASA, material from Comet ISON appeared on the other side of the sun on the evening on November 28, 2013, despite not having been seen in observations during its closest approach to the sun.
As ISON appeared to dim and fizzle in several observatories and later could not be seen at all by NASA's Solar Dynamics Observatory or by ground based solar observatories, many scientists believed it had disintegrated completely. However, a streak of bright material streaming away from the sun appeared in the European Space Agency and NASA's Solar and Heliospheric Observatory later in the evening. NASA scientist have yet to determine whether it is merely debris from the comet, or if some portion of the comet's fragile nucleus survived, but late-night analysis from scientists with NASA's Comet ISON Observing Campaign suggest that there is at least a small nucleus intact.
Before it neared the sun, Comet ISON (officially known as C/2012 S1) was less than 3 miles in diameter, about the size of a small mountain, and weighed between 7 billion and 7 trillion pounds. Like all comets, ISON is a dirty snowball made up of dust and frozen gases such as water, ammonia, methane and carbon dioxide. These are some of the fundamental building blocks which, scientists believe, led to the formation of the planets 4.5 billion years ago.
Comet ISON is believed to come from the distant Oort Cloud, a roughly spherical collection of comets and comet-like structures that exists in a space between one-tenth light-year and 1 light-year from the sun.
The comet was discovered Sept. 21, roughly between Jupiter and Saturn, by Vitali Nevski and Artyom Novichonok at the International Scientific Optical Network (ISON) near Kislovodsk, Russia.
Image Credit: ESA/NASA/SOHO/GSFC