A group of sunspots 11 times wider than the Earth turned to face our planet, raising the possibility of solar flares and auroras tonight.
More than 60,000 miles wide, Sunspot Region 1476 became visible over the weekend and two coronal mass ejections (CMEs), where a portion of the sun's atmosphere breaks off, erupted on Tuesday.
The CMEs blasts could arrive on Earth later today and cause moderate geomagnetic storms later and auroras in the higher latitudes, according to NOAA's Space Weather Prediction Center.
The CMEs are traveling at 1.5 million miles per hour but, since they are only partially directed at Earth, they aren't expected to affect communications satellites or other equipment susceptible to space weather. (Special filters are needed for viewing the sun directly to protect the eye, notes Space.com.)
Scientists at NASA's Space Dynamics Observatory called Sunspot Region 1476 a "monster sunspot" because it is so large and noticeable. The spot is so large that people have been able to see it without the aid of telescopes, said Spaceweather.com. Photographers should only view it through the camera's LCD, it warns.
Sunspots are caused by strong magnetic fields inside the sun's cores, which sometimes result in solar flares where high-energy particles are sent off into space.
The sun goes through cycles where the twisting magnetic fields in the core build up strength and cause an increase in solar flares. The sun is approaching a "solar maximum" next year.