A powerful burst of solar energy erupted from the surface of the Sun in the early hours of June 15, unleashing the most intense solar flare of the month—a highly energized M8.4-class event—accompanied by a coronal mass ejection (CME) that is now partially en route to Earth. According to Russia’s foremost solar observatories, the Earth-facing component of the flare is expected to brush the planet’s magnetic field between June 17 and 18, potentially sparking geomagnetic disturbances.
Although the main body of the solar plasma appears to have missed Earth’s direct orbital path, a tangential plume of the energetic particles was observed heading toward the planet. Russian space scientists have stated that the impact will likely result in a low-grade G1 geomagnetic storm—enough to generate auroras at high latitudes and possibly disrupt radio frequencies, but not powerful enough to threaten global infrastructure.
Russia confirms high-level solar activity with minimal threat to Earth
A powerful M8.4-class solar flare erupted from the Sun on June 15, 2025, marking the most intense solar event observed this month, according to Russian space weather observers. The flare was accompanied by a partial coronal mass ejection (CME), with experts confirming that while most of the plasma missed Earth’s orbital plane, a smaller fragment is traveling in our direction and is expected to reach Earth between June 17 and 18.
According to Russian Fontanka, the plasma ejection is projected to cause a G1-class geomagnetic storm, the lowest level on the international scale, indicating minor but detectable effects. These may include increased auroral activity in high-latitude areas, slight interference with satellite communications, and brief disruptions to high-frequency radio signals. As reported by Interfax, space agencies are on alert for additional M-class solar flares this week, with a 100% probability of recurrence and a 20% chance of a more severe X-class flare, according to forecasts cited by Russian Klops.
June flare marks the strongest of the month, with more to come
According to Russian Klops, which cited the Institute of Applied Geophysics (IPG) in Moscow, the M8.4 event is the strongest recorded flare in June 2025 so far. On a scale used by space scientists, M-class flares are second only to X-class flares in magnitude and can be powerful enough to disrupt communication, navigation, and satellite systems.
The flare lasted approximately 18 minutes and emitted a significant level of X-ray radiation, said a spokesperson from the IPG. We are currently in a phase of heightened solar activity, and there is a near-100% chance of more M-class flares occurring in the next 48 hours. We are also monitoring the possibility of an X-class flare, with a likelihood of around 20%.
G1-class geomagnetic storm likely: What does that mean?
Space weather monitoring stations including those in Russia and aboard international satellites estimate that the upcoming interaction will produce a G1-class geomagnetic storm, the mildest category on the NOAA space weather scale. Such events are generally harmless to the public but may affect high-frequency (HF) communications, GPS reception, and polar flight navigation systems.
The approaching solar wind could also cause minor fluctuations in electrical grid voltages and increase drag on satellites in low Earth orbit. While there is no immediate danger, satellite operators, airline companies, and power infrastructure managers have been advised to remain alert through June 18, accoring to Russian Interfax.
Scientists urge vigilance as solar maximum nears
The flare is part of a larger pattern of increasing solar activity as the Sun approaches the peak of its 11-year solar cycle, expected between late 2025 and early 2026. During such periods, sunspot numbers rise, and so does the frequency of flares and CMEs.
This is a textbook M8.4 event, explained Dr. Yuri Ivanovich, a solar physicist with the Russian Institute of Solar Dynamics. “Even though most of the plasma won’t hit Earth head-on, the glancing interaction is enough to induce a low-level magnetic storm and temporarily disturb space-based communications. What we’re seeing now is just a preview of what might come later in the cycle.
What can be affected?
- Auroras: Enhanced auroral displays are expected in Arctic and sub-Arctic regions. Observers in northern Russia, Alaska, and parts of Canada may be able to see auroras on June 17–18.
- Radio Signals: HF radio users, including aviation and maritime operators, could notice intermittent signal loss.
- Satellites: Increased atmospheric drag may affect orbiting satellites, including Starlink constellations and weather satellites.
- Power Infrastructure: Although unlikely in G1-class storms, grid managers are monitoring for any voltage irregularities.
Could an X-class flare follow?
While the current solar flare poses limited risk, experts warn that more intense events may follow. Historically, M-class flares have often preceded stronger X-class events. The most dangerous solar storms in history—such as the 1859 Carrington Event—originated from high-magnitude flares and direct CME impacts.
Solar behavior is notoriously difficult to forecast, said Dr. Ivanovich. But we’re in a cycle upswing, and solar active regions are becoming more dynamic. We strongly recommend continuous monitoring for any escalation.
