NASA has assembled a corps of comet experts at Kitt Peak this week to observe Comet ISON with the McMath-Pierce Solar Telescope and keep track of the comet through its armada of space telescopes.

Today (Wednesday) ISON began to act like a true sun-grazing comet, brightening significantly as it approaches perihelion on Thursday.

It is now as bright as a planet, having brightened to negative magnitude. It's too close to the sun to see, although astronomers had hoped to obtain spectra using McMath-Pierce. They were thwarted today by the astronomers' nemesis — cloud cover.

Tomorrow should be sunny and they'll try again.

The big question: Will it vaporize or survive to become a show in the early morning and evening sky?

The quickest way to find out is by following the writings of the NASA Comet ISON Observing Campaign where comet experts Matthew Knight and Karl Battams are blogging ISON's behavior from their posts at the venerable solar telescope. Read them at: http://www.isoncampaign.org/

The team is led by Jeff Morgenthaler of Tucson-based Planetary Science Institute, who hopes this gathering is added evidence of the need to keep McMath-Pierce operating after the National Solar Observatory moves its research operations to the Advanced Technology Solar Telescope in Hawaii.

Morgenthaler is part of a consortium that is seeking funding to keep Kitt Peak's icon alive as NSO ramps down its funding to zero over the next four years.

The telescope, in case you don't recognize it, is the image at the top of the Scientific Bent blog.