First Solar Storm in a While Headed for Earth

Bad Astronomy
The entire universe in blog form
March 16 2013 1:20 PM

The Sun Woke Up Yesterday

solar storm
The solar eruption as seen by the NASA/ESA Sun-observing satellite SOHO. The wave of particles can be seen to the upper left; the Sun's disk itself is blocked to show fainter objects.

Image credit: NASA/ESA/SOHO/helioviewer.org

The Sun’s been quiet lately, which is weird. We should be heading for the peak of its 11 year magnetic cycle, when it should erupt pretty often with sunspots, solar flares, and gigantic storms called coronal mass ejections (CME).

Phil Plait Phil Plait

Phil Plait writes Slate’s Bad Astronomy blog and is an astronomer, public speaker, science evangelizer, and author of Death From the Skies!  

But it’s been holding its tongue the past few weeks. There have been sunspots, but not many, and none very big. There have been surprisingly few eruptive events, too.

Advertisement

On Mar. 15, around 06:00 UTC (02:00 Eastern U.S. time) the Sun blew out a decent-sized CME, and it’s headed toward Earth. This isn’t a very big one, so the effects will probably be moderate at best, but it could produce some aurorae if you live at a high latitude (farther north than about 45°, and farther south than -45°). It could hit as early as tonight.

In the video, made using data from the NASA/ESA SOHO satellite, the Sun is blocked by a metal disk to allow fainter material to be seen. Both Venus and Mars are in the frame, and you can see stars moving in the background as well.

There’s nothing to fear here, I’ll add. You won’t turn into the Hulk, and this won’t spark a global apocalypse. In general these happen all the time. This one’s noteworthy because it’s the first in a while.

You can also see it in this wonderful time-lapse video taken using the Sun-observing STEREO-B spacecraft, currently over 250 million kilometers away. From its viewpoint it can see the Sun (off the frame to the left), the Earth (far right), Mercury (left), and the incredible comet Pan-STARRS (which is obvious enough). The CME erupts right at the end (I have a longer description of this spacecraft and the comet in a previous post).

In the video it looks like the CME will hit the comet, but it may not. You’re seeing objects at very different distances here, all compressed in the third dimension. From STEREO-B’s perspective, the comet is in the foreground, tens of millions of kilometers closer than Earth is. The CME at the end is headed toward us, and may miss the comet entirely.

It’s interesting that the Sun has been quiet lately. Things were ramping up pretty well there for a while, then it petered out. I noticed this a couple of months ago while doing some research for a blog post, and I’ve had folks email me about it. Here’s a graph from the Space Weather Prediction Center showing sunspot number over time, which is a pretty good indicator of solar activity:

sunspot numbers
The number of sunspots seen over the past few years plotted with time. Note how the number is far lower than expected for the past few months.

Image credit: Space Weather Prediction Center

The black dots are the number of visible sunspots; the blue line a monthly average, and the red line the predicted future number. As you can see, we hit the solar minimum in 2008-2009, and it started heading back up in late 2010. We should be nearing or at the peak now, but for some reason the sunspot number stalled in late 2012. There was a huge peak in late 2011, then a huge drop in early 2012, so clearly the Sun is undergoing some sort of magnetic hiccupping. We may still see a big jump later this year, or it may simply slack off from here. The magnetic field of the Sun is fiercely complex and extremely difficult to understand.

The minimum in 2009 lasted nearly two years, far more than usual, so everyone expected this peak to be a little weird, too. Ironically, it’s living up to our expectations by behaving unexpectedly. As usual, we'll just have to wait and see what it does.


Tip o' the occulting disk to Alice Enevoldsen and SungrazerComets on Twitter.

TODAY IN SLATE

Politics

The Right to Run

If you can vote, you should be able to run for public office—any office.

Move Aside, Oxford Comma, the New Battle Is Over Single or Double Quotes

Renée Zellweger’s New Face Is Too Real

Sleater-Kinney Was Once America’s Best Rock Band

Can it be again?

Ben Bradlee’s Fascinating Relationship With JFK

Culturebox

The Simpsons World App Is Finally Here

I feel like a kid in some kind of store.

Technology

Driving in Circles

The autonomous Google car may never actually happen.

My Father Invented Social Networking at a Girls’ Reform School in the 1930s

How Punctual Are Germans?

  News & Politics
The World
Oct. 22 2014 11:57 AM Why Wasn't the WHO Ready for Ebola?
  Business
Moneybox
Oct. 21 2014 5:57 PM Soda and Fries Have Lost Their Charm for Both Consumers and Investors
  Life
Atlas Obscura
Oct. 22 2014 12:03 PM Colonia Fara: An Italian Summer Camp for Happy Little Fascists
  Double X
The XX Factor
Oct. 22 2014 10:00 AM On the Internet, Men Are Called Names. Women Are Stalked and Sexually Harassed.
  Slate Plus
Working
Oct. 22 2014 6:00 AM Why It’s OK to Ask People What They Do David Plotz talks to two junior staffers about the lessons of Working.
  Arts
Behold
Oct. 22 2014 11:04 AM Do All U.S. Presidents Look the Same? What About Japan’s Prime Ministers?
  Technology
Technology
Oct. 22 2014 10:29 AM Apple TV Could Still Work Here’s how Apple can fix its living-room product.
  Health & Science
Science
Oct. 22 2014 11:30 AM Where Does Ebola Hide? My nerve-wracking research with shrieking bats.
  Sports
Sports Nut
Oct. 20 2014 5:09 PM Keepaway, on Three. Ready—Break! On his record-breaking touchdown pass, Peyton Manning couldn’t even leave the celebration to chance.