Comet ISON May have Survived: New Observations Reveal Comet's Fate

One question has plagued astronomers about the sungrazing Comet ISON: Did it survive its trip around the Sun, or did it disintegrate? If it survived perihelion on Nov. 28, we may be in for a spectacular light show over the next few days. But if it fizzled, we'll likely never see the comet again.

Comet ISON, also known as Comet C/2012 S1, was first discovered on Sept. 21 2012 by astronomers Artyom Novichonok and Vitali Nevski. At the time, the comet was very faint with a brightness of only magnitude 18 or so; the faintest you can see with your eye is about magnitude 7. Further study of the comet, though, showed that the astronomers had discovered something extraordinary. Comet ISON had the potential to graze the sun and produce a spectacular display with a long tail that could even be seen in daytime skies--assuming it survived its encounter with the Sun.

Initial reports actually seemed unfavorable toward the comet. In fact, ISON seemed 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. This led scientists to believe that the comet had fizzled, disappointing both astronomers and the public who had hoped for the "comet of the century." Now, though, it seems that ISON might just have survived, according to the Goddard Space Flight Center.

Later in the evening, the European Space Agency and NASA's Solar and Heliospheric Observatory caught a streak of bright material streaming away from the Sun. The current question is if this bright material is merely debris from the comet, or if some portion of the comet's nucleus survived. Late-night analysis from scientists with NASA's Comet ISON Observing Campaign, though, suggests that at least a small part of the comet's nucleus is still intact.

As of Nov. 30, Comet ISON was a faint, diffuse cloud with no obvious central condensation, according to NASA. Currently, scientists are keeping their eyes to the skies as they wait for more information about the comet. Only then will they know if they'll get a few more images before the comet fizzles out completely.

Even so, scientists will get quite a bit of information out of the comet. Researchers have been watching comet ISON for about the year and have observed it brightening and dimming in unexpected ways. Such brightness changes usually occur in response to material boiling off the comet, and different material will do so at different temperatures. This, in turn, will provide clues as to what the comet is made of, which will help inform future comet predictions. 

Want to learn more about the comet? Check out the Observing Campaign here.