Much anticipated comet may be in trouble

Amanda Barnett, CNN
Updated 2:24 AM EST, Wed November 27, 2013
Comet ISON appears as a white smear heading up and away from the sun on Thursday, November 28. Scientists initially thought the comet had been disintegrated by the sun, but images suggest a small nucleus may still be intact.
Comet ISON —
Comet ISON appears as a white smear heading up and away from the sun on Thursday, November 28. Scientists initially thought the comet had been disintegrated by the sun, but images suggest a small nucleus may still be intact.
SOHO/GSFC/ESA/NASA
Comet ISON is seen, top left, after its close encounter with the sun on November 28. In this picture, called a coronagraph, the bright light of the sun is blocked so the structures around it are visible.
Comet ISON —
Comet ISON is seen, top left, after its close encounter with the sun on November 28. In this picture, called a coronagraph, the bright light of the sun is blocked so the structures around it are visible.
SOHO/ESA/NASA
Comet ISON moves close to the sun at 10:51 a.m. ET on November 28.
Comet ISON —
Comet ISON moves close to the sun at 10:51 a.m. ET on November 28.
ESA/NASA/SOHO/SDO
Comet ISON's position is seen near the sun at 9:30 a.m. ET on November 28. This composite image comes from NASA and the European Space Agency.
Comet ISON —
Comet ISON's position is seen near the sun at 9:30 a.m. ET on November 28. This composite image comes from NASA and the European Space Agency.
ESA/NASA/SOHO/SDO
Comet ISON is seen early on Wednesday, November 27.
Comet ISON —
Comet ISON is seen early on Wednesday, November 27.
ESA/NASA/SOHO
Comet ISON shines brightly on the morning of November 19. The comet was discovered by Russian astronomers Vitali Nevski and Artyom Novichonok in September 2012. It was named after their night-sky survey program, the International Scientific Optical Network.
Comet ISON —
Comet ISON shines brightly on the morning of November 19. The comet was discovered by Russian astronomers Vitali Nevski and Artyom Novichonok in September 2012. It was named after their night-sky survey program, the International Scientific Optical Network.
Cameron McCarty/MEO/MSFC/NASA
Comet ISON, right of center in the frame and distinguishable by it's tail, is seen in this photo taken by a crew member aboard the International Space Station on Saturday, November 23.
Comet ISON —
Comet ISON, right of center in the frame and distinguishable by it's tail, is seen in this photo taken by a crew member aboard the International Space Station on Saturday, November 23.
NASA
Comet ISON, with Comet Encke ahead, is pictured along with Mercury and Earth in this image taken by NASA's solar-observing STEREO spacecraft on Friday, November 22.
Comet ISON —
Comet ISON, with Comet Encke ahead, is pictured along with Mercury and Earth in this image taken by NASA's solar-observing STEREO spacecraft on Friday, November 22.
Karl Battams/NRL/NASA STEREO/CIOC
Comet ISON is seen through blue and red filters on November 2.
Comet ISON —
Comet ISON is seen through blue and red filters on November 2.
Hubble Heritage Team/ESA/NASA
A series of photos shows how Comet ISON changed its appearance as it approached the sun.
Comet ISON —
A series of photos shows how Comet ISON changed its appearance as it approached the sun.
courtesy Efrain Morales Rivera
Comet ISON, which was brightening as it approached the sun, is shown here on October 25.
Comet ISON —
Comet ISON, which was brightening as it approached the sun, is shown here on October 25.
Marshall Space Flight Center/NASA
Despite the very bright full moon on October 20, Comet ISON was showing a long tail.
Comet ISON —
Despite the very bright full moon on October 20, Comet ISON was showing a long tail.
courtesy Gianluca Masi
Color filters help create this vivid image of Comet ISON, captured by NASA's Hubble Space Telescope on April 30.
Comet ISON —
Color filters help create this vivid image of Comet ISON, captured by NASA's Hubble Space Telescope on April 30.
NASA, ESA, Hubble Heritage Team