A geomagnetic storm is threatening radio communications Monday night, but that doesn’t mean you should be concerned. In fact, it may be an opportunity to see a colorful aurora in the night sky.

The National Oceanic and Atmospheric Administration has issued a geomagnetic storm watch after witnessing a coronal mass ejection from the sun on Saturday. The watch, which was issued over the weekend and will expire after Monday, said the onset of the storm passing over Earth on Sunday night represented a «moderate» threat to communications. As the storm continues to pass through, it could deliver a «strong» threat on Monday night that could cause radio communications to be temporarily disrupted during the worst of it.

Even so, NOAA said, «the general public should not be concerned.»

A coronal mass ejection occurs when magnetic field and plasma mass are violently expelled from the sun’s corona, or the outermost portion of the sun’s atmosphere. In the vast majority of cases, the ejection occurs with no real threat to Earth. However, in the event the ejection happens in the planet’s direction, a geomagnetic storm occurs, and the Earth’s magnetic field is temporarily affected.

In most cases, geomagnetic storms cause little to no disruption on Earth, with radio communications and satellites affected most often. In extreme cases, a geomagnetic storm can cause significant and potentially life-threatening power outages — a prospect that, luckily, the planet hasn’t faced.

Switching poles

Every 11 years, the sun’s magnetic poles switch, with the north pole and south pole swapping positions. During those cycles, the sun’s activity ramps up as it gets closer to pole-switching time. The height of its activity is called solar maximum, and scientists believe we either may be entering the solar maximum or may be already in it.

During periods of heightened solar activity, sunspots increase on the sun and there’s an increase in coronal mass ejections, among other phenomena. According to NOAA, solar maximum could extend into October of this year before the sun’s activity calms and it works towards its less-active phase, solar minimum.

Even when geomagnetic storms hit Earth and disrupt communications, the effects are usually short-lived. Those most affected, including power grid operators and pilots and air traffic controllers communicating over long distances, have fail-safe technologies and backup communications to ensure operational continuity.

But geomagnetic storms aren’t only about radios. In most cases, they also present unique opportunities to see auroras in the night sky. When the storms hit, the plasma they carry creates a jaw-dropping aurora, illuminating the night sky with brilliant colors. Those auroras can be especially pronounced during the most intense phases of the storm, making for nice stargazing.

If you’re interested in seeing the aurora, you’ll need to be ready. The NOAA said the «brunt of the storm has passed» and even if it lingers into Tuesday, there won’t be much to see after Monday night.