The latest Comet ISON update is that the comet--which is hurtling towards the sun--is now visible from Earth. To the naked eye.
The human eye can perceive objects as faint as +6.5 magnitude.
Veteran comet observer John Bortle told Space.com that the comet was at +8.5 on Monday and +7.3 on Wednesday, but had brightened to +5.4 on Thursday.
“Ready to go at 4:45 a.m. but I couldn’t figure out what the funny-looking, blotted, star that came into view was,” Bortle said. “(Was my) seeing that bad? But, no, the ‘blotted star’ was, in fact, at the comet’s position! Getting to the point, the little but intensely condensed, globular cluster-looking comet was a whopping magnitude 5.4 — two full magnitudes brighter than just 24 hours ago! This makes for a three-magnitude total rise since my observation on Monday.”
The comet’s blazing green trial is a result of the release of primitive dust and ice, Diane Wooden, an astrophysicist at NASA, told the Daily News.
“We are seeing the first heating of the body and the first releasing of the volatile ices and dust grains in the sunlight,” she said. “The last comet that did this in a predictable way was Comet Ikeya-Seki in 1965.”
“When it goes too close to the sun it’s like the entire surface is released,” Wooden said.
The comet is approaching the Sun, and should pass by at a little more than a million kilometers from the sun’s surface, an encounter it may or may not survive. Because its orbit is bringing it so close to the sun, it is called a sungrazer.
“If the comet survives–a big IF–it could emerge glowing as brightly as the Moon, briefly visible near the sun in broad daylight. The comet’s dusty tail stretching into the night sky could create a worldwide sensation,” according to NASA.
