Solar activity can definitely affect Earth, but for people on the ground it’s mostly a risk to our technology and infrastructure, not to our bodies.

What “solar activity” means

When people talk about dangerous solar activity, they usually mean:

  • Solar flares (sudden bursts of radiation from the Sun).
  • Coronal mass ejections, or CMEs (huge blobs of magnetized plasma blasted into space).
  • High‑energy particle storms (fast protons and other particles).

These events tend to peak around solar maximum, the most active phase of the Sun’s roughly 11‑year cycle.

Main risks to Earth

1. Power grids and infrastructure

This is the biggest civilizational‑scale concern.

  • CMEs can induce strong electrical currents in long power lines, pipelines, and undersea cables.
  • Those currents can overload or damage transformers, relays, and circuit breakers, leading to regional blackouts.
  • A very extreme storm (a “Carrington‑class” event) could cause widespread power outages and economic damage, but such events are rare.

2. Satellites and GPS

Satellites sit above much of Earth’s atmospheric shielding, so they’re more exposed.

  • High‑energy particles can degrade solar panels and damage satellite electronics and sensors.
  • Increased drag from a heated, “puffed‑up” upper atmosphere can change satellite orbits, potentially making them lose altitude.
  • Navigation systems (GPS, GNSS), Earth‑observation satellites, and communication satellites can all experience glitches or temporary failures during strong storms.

3. Radio, communications, and navigation

Solar storms can disrupt how radio waves travel through the ionosphere.

  • High‑frequency (HF) radio used by aviation, ships, and the military can experience blackouts, especially near the poles and on the Sun‑facing side of Earth.
  • Some geomagnetic storms have caused short‑term loss of shortwave radio and degraded long‑range communication.
  • Navigation accuracy from GPS can temporarily worsen during intense space‑weather events.

4. Aviation and astronauts

For most passengers, flights remain safe, but there are operational considerations.

  • High‑altitude, high‑latitude flights (e.g., polar routes) can get elevated radiation doses during major particle events, so airlines may reroute or change altitudes.
  • Astronauts in low Earth orbit are partly shielded by Earth’s magnetic field but still face increased radiation risk during big storms.
  • Astronauts traveling beyond Earth’s magnetosphere (e.g., to the Moon or Mars) would be especially vulnerable to powerful solar particle events without heavy shielding.

5. Internet and undersea cables

Modern studies highlight vulnerability beyond just the power grid.

  • Geomagnetically induced currents can flow through long undersea and terrestrial communication cables.
  • This can stress repeaters and other electronics, raising the risk of regional Internet disruptions during extreme storms.

What about direct risk to people?

On the ground, the direct risk to human health from solar activity is extremely low.

  • Earth’s atmosphere and magnetic field block or absorb the vast majority of harmful radiation from solar flares and CMEs.
  • Geomagnetic storms are not considered dangerous to human bodies at Earth’s surface.
  • The realistic concern for most of us is losing power, navigation, or communications for a period of time, not radiation sickness.

How society manages the risk

Scientists and agencies treat solar storms like other low‑frequency, high‑impact hazards.

  • Space‑weather monitoring (NASA, NOAA, other agencies) watches the Sun and provides alerts to grid operators, satellite companies, and airlines.
  • Grid operators can take protective actions: adjusting power flows, temporarily taking sensitive transformers offline, or using grounding strategies to reduce damaging currents.
  • Satellite and aviation operators use forecasts to schedule maneuvers, protect electronics, or change flight paths.

A simple way to think about it: solar activity can’t “burn the Earth,” but in a worst‑case scenario it could temporarily knock out parts of the technological shell we’ve built around the planet—power, satellites, and communications—until repairs are made.

TL;DR: The potential risks from solar activity are mainly to power grids, satellites, communications, and high‑altitude/space travelers; people on the ground are well protected by Earth’s atmosphere and magnetic field.

Information gathered from public forums or data available on the internet and portrayed here.