ISON has continued to brighten in recent days, becoming visible to the naked eye in the early-morning sky above the eastern horizon. Recent footage of the comet has been spectacular, but ISON could become harder to spot as it continues on its inexorable dive toward the Sun.
Bright though ISON may be, it's becoming increasingly difficult for the ball of ice and dust to outshine the pre-dawn light of our parent star. The timelapse footage above shows what ISON looked like from the Teide observatory in the Canary Islands on the morning of November 22nd. At the time, Universe Today's Nancy Atkinson predicted it was likely to be the last glimpse we'd get of ISON.
"The comet was over the distant island of Gran Canaria above a sea of clouds about 1 hour before sunrise and only 16° from the sun," said Casado, who brought the comet into view against the ember-like glow of twilight by stacking four photos into the composite image seen here (for details on his shooting specs, see here). "The exceptional atmospheric conditions of Teide Observatory allowed me to capture the image."
Composites like Casado's could be the last ground-based images we see of the so-called "sun-grazing" comet – at least on this leg of its solar flyby; ISON will continue on its scorching solar approach until November 28th, when it will sweep within 730,000 mles of the Sun. If it manages to survive its fiery dance with death, there's a chance it could emerge a blazing ball of light – a "comet of the century," visible, perhaps, even in the light of day.
Whether ISON will survive its flyby at all, however, remains to be seen. And see it we will. While the comet may pass from our sight here on Earth, there are plenty of spacecraft – including NASA's STEREO, the Solar and Heliospheric Observatory (SOHO) and the Solar Dynamics Observatory (SDO) – keeping tabs on it as it approaches the Sun.
Whether it breaks up on approach or makes it out alive, we'll keep you posted on ISON's progress here, though NASA's Comet ISON website is also an excellent resource. Keep your eyes peeled and your fingers crossed for a comet of the century!