Astronomers spot gigantic 'hole' in sun

A hole in the topmost layers of the sun's corona is making for spectacular auroras here on Earth.

NASA/SDO
A photo of the sun from NASA's orbiting Solar Dynamics Observatory reveals an enormous coronal hole — a gap in the sun's outer layer and magnetic field the size of 50 Earths.
NASA/SDO
A Solar Dynamics Observatory image published by the National Oceanic Atmospheric Administration reveals the huge coronal hole as it was yesterday.

The sun has sprung a leak: A hole in the topmost layer of the sun and its magnetic field, the size of 50 Earths, is letting loose an ultrafast solar wind that has kicked off several nights of auroras down on Earth.

A new image, from NASA's orbiting Solar Dynamics Observatory, reveals the enormous hole as it was Oct. 10, taken at an ultraviolet wavelength unseen by the human eye. To an ordinary observer, the gaping hole would be invisible, though you should NEVER stare at the sun because serious eye damage can result.

The gap in the sun's magnetic field lets out a stream of particles traveling at up to 500 miles (800 kilometers) per second, kindling a days-long geomagnetic storm upon hitting Earth. [Biggest Solar Storms of 2015 in Photos]

Coronal holes, like the one that materialized last week, normally form over the sun's poles and lower latitudes, more often when the sun is at a less active point in its 11-year cycle. They are areas within the sun's outermost layer, called its corona, which are lower-density and cooler — that, plus the weakened magnetic field, lets the plasma and charged particles that make up the corona stream out more easily in a solar wind. If aimed toward Earth, that spells the makings of a geomagnetic storm: a phenomenon that can affect power and navigation for satellites orbiting the Earth as well as radio communication.

Another side effect of a geomagnetic storm is enhanced northern lights: the glowing auroras that often form in the night sky over the northernmost reaches of the planet grow much brighter and can even extend much farther south than usual. (Last week, the National Oceanic and Atmospheric Administration's [NOAA] Space Weather Prediction Center in Boulder, Colorado, initially predicted auroras to be visible as far down as Pennsylvania, Iowa and Oregon, although they didn't ultimately appear quite so low.) Geomagnetic storms and auroras can also be caused by other sun phenomena, such as solar flares and coronal mass ejections, which both blast the corona's material outward because of increased magnetic activity.

As the coronal hole continues its slow march westward on the sun's surface (to the right, from Earth's perspective), solar winds will stay strong, NOAA officials said in a statement, which may lead to additional minor geomagnetic storming. Thus, bright auroras will likely continue — at least around the Arctic Circle.

Email Sarah Lewin at slewin@space.com or follow her @SarahExplains. Follow us @Spacedotcom, Facebook and Google+. Original article on Space.com.

Copyright 2015 SPACE.com, a Purch company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.

You've read  of  free articles. Subscribe to continue.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Astronomers spot gigantic 'hole' in sun
Read this article in
https://www.csmonitor.com/Science/2015/1018/Astronomers-spot-gigantic-hole-in-sun
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe