Two great links for learning more about Comet ISON at perihelion today:
Everything you need to know: Comet ISON
Today’s the day. Comet ISON has traveled a light-year’s distance, and over a million years of time, from the Oort comet cloud surrounding our solar system. Today, ISON will encounter the sun. If it survives this encounter – and things are looking very good at this moment – Comet ISON may go on to become a beautiful comet in Earth’s sky.
Experience Comet ISON’s encounter with the sun online
Links to various opportunities for chats with experts and real-time images.
Comet ISON brightened dramatically within the past 24 hours (although the latest word is that its brightness has now dropped a bit). On November 27, its brightness was beginning to overwhelm the detector of the SOHO mission’s LASCO C3 instrument. That’s why NASA’s Karl Battams, who labeled this image, marked the saturation spike. The spike is not really part of the comet; it’s just an artifact on the image created by so much brightness.