Give Now

Comet ISON Expected To Pass Into Inner Solar System Thursday

Comet ISON shines in this five-minute exposure taken at NASA's Marshall Space Flight Center on Nov. 8, 2013.

A comet called ISON will make its first passage into inner solar system on Thanksgiving Day.

The comet was discovered last year by Russian astronomers.

“The unique thing about it is that this is what we call a sun grazer,” says Butler University Astronomy Professor Brian Murphy. “This is going to pass just barely above the solar surface, so it will be heated to pretty high temperatures.”

Murphy says that means there is no telling what will come out on the other side of the sun.

“It won‘t fall into the sun because the sun is putting out so much radiation, and the path of this thing is well calculated,” says Murphy. “It‘s just the shear closeness that means we can‘t make exact predictions.”

Murphy says the comet has unusually high carbon dioxide content, in part because it is new to our solar system.

“It‘s made up of water — ice and carbon dioxide — dry ice basically, and dust. So, whether it breaks up or survives — comes out the other side, that will give us our clues as to whether we will see an early December comet in our skies,” he says.

Murphy says whatever is left of ISON should be visible from the earth sometime on Sunday. Looking directly at the sun as the comet passes could cause eye damage, but you can watch ISON’s passage at

Want to contact your legislators about an issue that matters to you? Find out how to contact your senators and member of Congress here.

What is RSS? RSS makes it possible to subscribe to a website's updates instead of visiting it by delivering new posts to your RSS reader automatically. Choose to receive some or all of the updates from Indiana Public Media News:

Support For Indiana Public Media Comes From