Total eclipse promises celestial show with streamers, loops and a possible comet

A total solar eclipse is a rare celestial event that always generates excitement, but next month's version is expected to be unusually spectacular.

A total solar eclipse is a rare celestial event that always generates excitement, but next month's version is expected to be unusually spectacular.

The April 8 eclipse that will occur over a large swath of North America, following a path that takes in parts of southern Ontario, Quebec and Atlantic Canada, comes as the sun's magnetic activity is at the peak of an 11-year cycle. That means that during the brief period when the moon totally covers the sun, a show of streamers and magnetic loops will dance around the obscured sun.

Paul Bryans, a scientist at the National Center for Atmospheric Research in Colorado, said that during times of low activity, the sun's corona — the tendrils of light that show the outer limits of the sun's energetic atmosphere — is homogeneous and symmetrical. But this year, he said, the heightened magnetism will make the sun's outer edges spiky like a hedgehog with its quills raised.

"So you have got lots of spikes and activity coming up in different places, and it's hard to really predict exactly where they will be," Bryans said. "But if you're looking at the eclipse, you wouldn't see a nice, smooth corona. You'll see, oh, jagged hedgehog in fear."

Normally, the blinding brightness of the sun means the activity cannot be seen with the naked eye, but the eclipse provides an opportunity to see the shards of light shooting out from the darkened sun. Experts warn that eye damage can result if you look directly at the sun, even during a partial eclipse, without protective eclipse glasses. When the moon completely blocks the sun, however, glasses can be removed to observe the sun's whitish corona.

In addition to causing the spikes, or streamers, the heightened magnetic activity means the sun will have features known as prominences, which Bryans described as looking like loops attached to the corona and held in suspension.

These prominences occur because the sun's magnetic activity is uneven across its surface. There are areas where the magnetic field is extremely high, causing eruptions so powerful that they can be felt on Earth in the form of interference in satellite communication or cellphone signals, Bryans said.