NASA has confirmed that ISON, the so-called “comet of the century,” was destroyed during its close pass by the Sun last week.
Astronomers at the International Scientific Optical Network in Russia discovered the new comet, C/2012 S1 or simply ISON, heading toward the Sun last September. At the time, there was talk that ISON could become extremely bright, possibly brighter than the full Moon, in late November and early December, after a close brush with our Sun.
It is extremely difficult to predict the brightness of a comet, especially so far in advance. Complicating the issue was the possibility that the comet’s close pass around the Sun could destroy it. If it did survive, though, astronomers agreed it would likely put on quite a show.
ISON emerged from behind the Sun in August, and was bright enough to be visible through small telescopes or binoculars. It was expected to become visible to the naked eye by late October or early November, and remain so until mid-January 2014.
The comet reached its perihelion on November 28, grazing the Sun as predicted. And, as feared, the comet fragmented on its pass.
Astrophysicist Karl Battams wrote the following tongue-in-cheek obituary for the comet earlier this week on NASA’s Comet ISON Observing Campaign site:
Comet C/2012 S1 (ISON)
Born 4.5 Billion BC, Fragmented Nov 28, 2013 (age 4.5-billion yrs old)
Born in a dusty and turbulent environment, comet ISON spent its early years being jostled and struck by siblings both large and small. Surviving a particularly violent first few million years, ISON retreated to the Oort Cloud, where it maintained a largely reclusive existence for nearly four billion years. But around 3-million B.C., a chance encounter with a passing star coerced ISON into undertaking a pioneering career as a Sungrazer. On September 21, 2012, ISON made itself known to us, and allowed us to catalog the most extraordinary part of its spectacular vocational calling.
Never one to follow convention, ISON lived a dynamic and unpredictable life, alternating between periods of quiet reflection and violent outburst. However, its toughened exterior belied a complex and delicate inner working that only now we are just beginning to understand. In late 2013, Comet ISON demonstrated not only its true beauty but a surprising turn of speed as it reached its career defining moment in the inner solar system. Tragically, on November 28, 2013, ISON’s tenacious ambition outweighed its ability, and our shining green candle in the solar wind began to burn out.
Survived by approximately several trillion siblings, Comet ISON leaves behind an unprecedented legacy for astronomers, and the eternal gratitude of an enthralled global audience. In ISON’s memory, donations are encouraged to your local astronomy club, observatory or charity that supports STEM and science outreach programs for children.