If a small piece Comet ISON survived its Thanksgiving close encounter with the sun, it certainly is not still alive, NASA has announced.

After appearing to emerge on the other side after its Thursday flyby, NASA concluded that regardless if it was ISON's nucleus or a speck of debris, it is gone by now What's more, Karl Battams, an astrophysicist who has been tracking ISON, wrote a blog post on IsonCampaign.org title "In Memoriam."

"Survived by approximately several trillion siblings, Comet ISON leaves behind an unprecedented legacy for astronomers, and the eternal gratitude of an enthralled global audience," wrote Battams, who participated with NASA's Comet ISON Observing Campaign (CIOC). "In ISON's memory, donations are encouraged to your local astronomy club, observatory or charity that supports STEM and science outreach programs for children."

NASA reported Monday in a press release that a tiny bright object made it past ISON's close encounter with the sun. Many experts believed it was a tiny piece of the comet's nucleus, but NASA remained skeptical and said it may have been a piece of debris. As the comet felt the gravitational pull of the sun and the intense heat, bits and pieces would have fallen off the space rock.

"Whether that spot of light was merely a cloud of dust that once was a comet, or if it still had a nucleus - a small ball of its original, icy material - intact, is still unclear," NASA reported. "It seems likely that as of Dec. 1, there was no nucleus left."

As Battams pointed out, ISON has fascinated scientists since Sept. 21, 2012, when the comet first appeared. Originally billed as, "the comet of the century," ISON was a near-Earth object that was not threatening, but close enough to see its tail light up the sky. All it had to do was make a trip around the sun and then it would fly right over Earth for everyone to see.

"Never one to follow convention, ISON lived a dynamic and unpredictable life, alternating between periods of quiet reflection and violent outburst," Battams wrote. "However, its toughened exterior belied a complex and delicate inner working that only now we are just beginning to understand."