Comets use the Sun as a gravitational anchor in their elongated trajectories that bring them through the inner solar system then back out to the far suburbs. The Sun gives comet life by radiating the icy object’s surface to create the sometimes spectacular head and tail that can grace our night sky.

The interactions can spell death for some comets, which get too close and vaporize. Others break apart under the strain. Some astronomers had speculated that Comet McNaught, the present darling of the skywatching world, might meet this latter fate.

There’s another interesting interaction about which little is known.

A few hours prior to Comet McNaught’s initial appearance in the SOHO spacecraft’s field of view this week, a coronal mass ejection (CME) lifted off the sun, billowing to the left in this animated image (note: that CME is no longer in the animation, which shows the most recent 48 hours of observations).

It got me to wondering what would happen if another CME (which is a cloud of electrified particles) erupted when McNaught was at it’s closest to the Sun. Such an eruption occurred in a strikingly similar event in 2003, when a CME slapped comet NEAT. Scientists “think they observed a kink propagating down the comet’s ion tail,” we reported then. Research on CME effects on comet Ikeya-Zhang are reported here.

So yesterday I asked Bernhard Fleck, a SOHO Project Scientist with the European Space Agency, about the possibility with McNaught.

Fleck: “I just checked the geometry of the orbit. The comet is indeed in front of the plane of sky. So a CME lifting off from the Eastern side of the Earth-facing hemisphere could indeed hit the comet. As for the effects of such a strike? No idea! Guess it depends on the magnetic configuration of the CME.”

Fleck speculated that such an event might cause the comet’s ion-tail to fragment, but things like this have been seen so rarely that nobody knows what might take place.

Of course, it’s also quite possible the Sun will remain utterly quite as the comet circles around and heads for deep space. We are, after all, just past the low point in the 11-year cycle of solar activity.