Pella Chronicle

January 7, 2013

Comets could light up 2013 skies

MATT MILNER
CNHI

OTTUMWA — It has been a very long time since backyard astronomers of the northern hemisphere have had a year like 2013 could become.

Space experts say there's a good chance people could see two major comets over the course of the year. The objects, called Comet Panstarrs and Comet Ison, could well be the brightest to observers north of the equator since Comet Hale-Bopp in 1997.

That's if everything goes right, though. Comets are notoriously unpredictable. There was a huge amount of hype for Halley's Comet, the best known visitor, last time it passed Earth. But the 1986 flyby generated a smudge in the sky that didn't live up to people's expectations.

According to earthsky.org, the closest Panstarrs will get is March 5, when it will be slightly farther away from us than the sun. The closest it will get to the sun comes five days later, and that's when the comet will likely be brightest. At best, it should be visible to the naked eye.

The second comet, Ison, which will pass by in late 2013, is the one experts believe could be the most spectacular in decades. But that potential comes with significant risk. Ison, according to Nasa, is expected to be a sungrazer. That means it will come very, very close to the sun's surface.

If a sungrazer holds together, the proximity means it takes a lot of heat, which should create a very large and luminous tail. Some experts say it could temporarily be as bright as a full moon.

But the full force of the sun can also tear sungrazers apart, which would effectively turn off the show. And that could happen well before people get a good look at it.

It's too soon to know whether either of the comets will live up to expectations. But if either one does, it could be a year to remember.