Huge Solar Eruption With Unknown Origin Could Be Flying Towards Earth

Astronomers have spotted a huge eruption of material that has been ejected from the sun—but they're not sure whether or not it's headed towards Earth.

The eruption, known as a coronal mass ejection (CME), was observed on Sunday. Coronagraph images—images of the sun's atmosphere—posted online by the European Space Agency's CME-detecting CACTUS software show the eruption blasting away from the sun's surface in the early morning.

Judith de Patoul, a space weather forecaster at the Royal Observatory of Belgium, tweeted that the CME had a "very large angular width" and asked, "Is this CME Earth-directed?"

"The strange thing is, analysts aren't certain which side of the sun it came from," a notice on SpaceWeather.com read on Monday. "Some clues suggest farside, others Earthside. If it is an Earthside event, it could reach us late on June 28th or June 29th."

Solar flare
Solar flares and other space weather events like CMEs can potentially cause disruption on Earth, though this is rare. This NASA/SDO image shows a solar flare erupting from the sun in November 2014. NASA/SDO

Knowing whether or not solar ejections are heading towards Earth is a key role for space weather scientists since these ejections can have an effect on modern technology.

Solar flares are a bit like the muzzle flash of a cannon, according to NASA—a burst of light that reaches Earth within minutes and also carries high-energy particles that interact with our atmosphere. If solar flares are the flash, then CMEs are the cannonball…except that cannonball is an immense cloud of plasma and magnetic field.

CMEs in particular can interact with Earth's own magnetic field and cause a geomagnetic storm, in which voltage control systems and navigation networks can be affected. Particularly strong CMEs might cause the collapse of entire grid systems and radio communication interference for days, according to the Space Weather Prediction Center. Fortunately, storms of this strength are very rare.

CMEs can be prepared for since they can take up to a few days to travel from the sun to our planet. The problem is that scientists aren't too sure what's happening with Sunday's CME because although ESA instruments detected it there's not enough data to tell which way it was facing.

Normally, scientists could turn to NASA's Solar Dynamics Observatory (SDO) for more information. However, key SDO solar instruments are currently unavailable due to a widespread power outage affecting the Stanford University campus where SDO's data center is located.

"From a coronagraph alone, there's some ambiguity about whether a CME is heading directly towards or away from Earth," Matthew Owens, professor of space physics at the University of Reading, told Newsweek. "The Solar Dynamics Observatory enables us to look for signatures on the near-side of the Sun and break that ambiguity. With those data currently unavailable, that's become more difficult."

Owens said it's possible to use other instruments that can help deduce which way the CME is headed, such as using coronagraph data from two separate spacecraft to get a stereo effect. However, the effectiveness of this method depends on the instruments' positioning.

And even if scientists aren't able to work out whether the CME is heading towards Earth it's unlikely that it will generate a widely disruptive geomagnetic storm.