Solar storm explained: How geomagnetic storms can affect internet, power outages, satellites

If you've never heard of a solar storm or geomagnetic storm, chances are you'll learn about those really quickly this weekend. Earth is under a severe G4 watch or geomagnetic storm watch for the evening of Friday, May 10.

The National Oceanic and Atmospheric Administration's Space Weather Prediction Center (SWPC) — a division of the National Weather Service — was monitoring the sun following a series of solar flares and coronal mass ejections (CMEs) that began Wednesday, May 8, 2024. Space weather forecasters issued a Severe (G4) geomagnetic storm watch for the evening of Friday, May 10. Additional solar eruptions could cause geomagnetic storm conditions to persist through the Mother's Day weekend.

Here's what that means and how that may affect you.

What happened? Why is there a solar storm or severe G4 watch?

According to the weather service, a large sunspot cluster has produced several moderate to strong solar flares since 5 a.m. Wednesday, May 8, 2024. At least five flares were associated with CMEs that appear to be Earth-directed. SWPC forecasters are monitoring NOAA and NASA’s space assets for the onset of a geomagnetic storm.

What is a solar storm? What are coronal mass ejections or CMEs?

A solar storm or geomagnetic storm is a space weather event directly involving the sun.

According to NOAA, "solar radiation storms occur when a large-scale magnetic eruption, often causing a coronal mass ejection and associated solar flare, accelerates charged particles in the solar atmosphere to very high velocities. The most important particles are protons which can get accelerated to large fractions of the speed of light. At these velocities, the protons can traverse the 150 million kilometers from the sun to the Earth in just tens of minutes or less. When they reach Earth, the fast-moving protons penetrate the magnetosphere that shields Earth from lower energy charged particles. Once inside the magnetosphere, the particles are guided down the magnetic field lines and penetrate into the atmosphere near the north and south poles."

NOAA explains coronal mass ejections as explosions of plasma and magnetic fields from the sun’s corona. Basically, solar flares are blasts of strong energy that come from the sun, and they're detected from our satellites.

CMEs cause geomagnetic storms when they are directed at Earth. Geomagnetic storms can impact infrastructure in near-Earth orbit and on Earth’s surface, potentially disrupting communications, the electric power grid, navigation, radio and satellite operations.

SWPC has notified the operators of these systems so they can take protective action. Geomagnetic storms can also trigger spectacular displays of aurora on Earth. A severe geomagnetic storm includes the potential for aurora to be seen as far south as Alabama and Northern California.

Where are the coronal mass ejections or CMEs?

As of 10 a.m. Friday, May 10, the CMEs were 93 million miles away, Shawn Dahl, a space weather forecaster at NOAA's Space Weather Prediction Center (SWPC) in Boulder, Colorado, said in a Friday morning media teleconference.

When was the last severe G4 watch from the National Weather Service?

This is a very rare event. The last time NOAA issued a severe G4 watch was in 2005.

The Space Weather Prediction Center says NOAA categorizes solar radiation storms using the NOAA Space Weather Scale on a scale from S1 to S5. The scale is based on measurements of energetic protons taken by the GOES satellite in geosynchronous orbit. A solar radiation storm can range from hours to days.

The SWPC forecasts the probability of S1 (a minor radiation storm) as part of its 3-day forecast and issues warnings for an expected S1 or higher event, such as the G4 storm predicted for Friday, May 10.

How to prepare for a solar storm?

Experts said hopefully the public will not have to do anything. The National Weather Service said people should always have a basic plan that includes having batteries, a radio, and perhaps keep a generator handy. These space weather events are very rare.

How can a solar storm cause problems to our power grid?

The Just the FAQs video above from USA TODAY explains how a solar storm can cause problems to our power grid, affecting communications, navigation, satellite and radio.

Will the G4 storm affect ATMs and cell phones?

According to the National Weather Service, experts have not seen space weather storms directly impact ATMs or cell phones. However, space weather storms can affect power grids, which would, in turn, affect ATMs and cell phone usage. The secondary impacts from that would be great, experts said Friday morning during the NOAA press conference.

There's a solar storm and severe geomagnetic storm watch in the US. Will I lose power? Will I lose internet? Will my cell phone work?

Experts on the NOAA call on Friday morning said if the solar storm reaches the G4 levels, the level of response could mean there could be some infrastructure effects, citing the power grid in North America. Space weather forecaster Shawn Dahl said, "we won't know until these CMEs arrive about 1 million miles from Earth," adding NASA satellites will help forecast the intensity. From there, the National Weather Service will begin to issue more warnings.

Dahl explained that tracking the CMEs gives experts some lead time: "Roughly, we're talking an average speed of 20 minutes to 45 minutes" to prepare.

What could be the worst situation on Earth? Could any cities in the US experience disruption in power?

Experts on the National Weather Service call on Friday morning said it was tough to say what the worst situation on Earth would be and whether cities in the U.S. could definitively experience disruption in power. Forecasters, however, have procedures in place, other organizations (such as FEMA) are being notified as a precaution, and alternate equipment is working. These organizations, they said, would know what's causing anything if the situation unfolds, and they would be able to take the proper steps to help mitigate any problems.

How do solar storms affect astronauts? Will astronauts on the International Space Station be affected?

According to NOAA, solar radiation storms cause several impacts near Earth, affecting power grids and communications. "When energetic protons collide with satellites or humans in space, they can penetrate deep into the object that they collide with and cause damage to electronic circuits or biological DNA. During the more extreme solar radiation storms, passengers and crew in high-flying aircraft at high latitudes may be exposed to radiation risk. Also, when the energetic protons collide with the atmosphere, they ionize the atoms and molecules thus creating free electrons. These electrons create a layer near the bottom of the ionosphere that can absorb High Frequency (HF) radio waves making radio communication difficult or impossible."

When’s the next rocket launch at Cape Canaveral, Florida? Mother's Day, Sunday, May 12: SpaceX Starlink

National Geospatial-Intelligence Agency navigational warning includes a SpaceX Starlink mission window that will open Sunday night. As of Friday, May 10, the SpaceX Starlink launch was still scheduled. Here's more info about it and how to tune in to live coverage:

• Mission: A SpaceX Falcon 9 rocket will launch a batch of Starlink internet satellites from Cape Canaveral Space Force Station.

• Launch window: 8:11 p.m. EDT Sunday, May 12, to 12:42 a.m. EDT Monday, May 13

• Location: Launch Complex 40

• Trajectory: Southeast

• Local sonic boom: No

• Booster landing: Drone ship out on the Atlantic Ocean

• Live coverage: If you want to watch live rocket launch coverage, FLORIDA TODAY's Space Team will provide updates at floridatoday.com/space, starting about 90 minutes before launch time. You can download the free app for iPhone or Android or type floridatoday.com/space into your browser.

Sangalang is a lead digital producer for USA TODAY Network-Florida. Follow her on Twitter or Instagram at @byjensangalang. Support local journalism. Consider subscribing to a Florida newspaper.

This article originally appeared on Florida Today: Solar storm, solar flares, G4 watch, geomagnetic storms: Things to know