Butterfly-shaped hole in the Sun's atmosphere stuns scientists—potential effects on Earth on September 14

The 'coronal hole' is roughly 310,680 miles wide in the sun's atmosphere.
UPDATED SEP 12, 2025
This image combines three images with different, but very similar, temperatures (Cover Image Source: NASA SDO)
This image combines three images with different, but very similar, temperatures (Cover Image Source: NASA SDO)

A colossal "coronal hole," roughly 310,685 miles (500,000 kilometers) wide, has opened up in the Sun's atmosphere, releasing a powerful stream of solar wind that is expected to reach Earth on September 14. Captured by NASA's Solar Dynamics Observatory, the gap has a unique butterfly-like appearance, as per Space Weather

Outer atmosphere of the Sun, as well as hot flare plasma, at 2.25 million Fahrenheit (Image Source: NASA SDO)
Outer atmosphere of the Sun, as well as hot flare plasma, at 2.25 million Fahrenheit (Image Source: NASA SDO)

Coronal holes are areas where the Sun’s magnetic field lines extend outward into space instead of looping back, allowing hot plasma to escape. This gives them a dark appearance. The departing solar wind, a flow of charged particles, is now traveling toward our planet.

Outer atmosphere of the Sun, as well as the cooler dense plumes of plasma (filaments and prominences) visible above the surface of the Sun at 90,000 Fahrenheit (Image Source: NASA SDO)
Outer atmosphere of the Sun, as well as the cooler dense plumes of plasma (filaments and prominences) visible above the surface of the Sun at 90,000 Fahrenheit (Image Source: NASA SDO)

The arrival of this solar stream could trigger G1 to G2-class geomagnetic storms, according to experts. The likelihood of these storms is amplified by the Russell-McPherron effect, a phenomenon that enhances the connection between the Sun's and Earth's magnetic fields during the weeks surrounding the equinoxes. The potential effects on Earth could include disruption to power grids and communication satellites, as well as spectacular aurora displays.

Outer atmosphere of the Sun - the corona at 3.6 million Fahrenheit. (Image Source: NASA SDO)
Outer atmosphere of the Sun - the corona at 3.6 million Fahrenheit. (Image Source: NASA SDO)

Coronal holes are vast, dark areas of the Sun's atmosphere, easily spotted in extreme ultraviolet and X-ray images, according to NASA. These holes are essentially gaps in the Sun's magnetic field where lines of force don't loop back to the surface. Instead, they extend far out into the solar system, acting like a superhighway for solar material. Because the magnetic field lines are "open," hot, charged plasma can easily escape, giving these regions a much lower density and making them appear dark. This escaping material forms the fast solar wind, which can travel at speeds of up to 700 kilometers per second.

This image of a coronal hole on the sun bears a remarkable resemblance to the 'Sesame Street' character Big Bird (Image Source: NASA/AIA)
This image of a coronal hole on the sun bears a remarkable resemblance to the 'Sesame Street' character Big Bird (Image Source: NASA/AIA)

Coronal holes can form at any point during the Sun's 11-year cycle, but they are more common during the solar minimum, when large, long-lasting holes often appear near the Sun's poles. These holes can also expand and shift toward the Sun's equator, directing their stream of charged particles toward Earth.

While the Sun's atmosphere is in flux, a separate celestial event is drawing the attention of stargazers in the Southern Hemisphere. On September 21, a partial solar eclipse will be visible, with the moon partially obscuring the sun. The eclipse is expected to reach its peak at 3:43 p.m. EDT.

Solar eclipse August 21, 2017 at 1:15 pm from Wisconsin, USA 85% Coverage (Image Source: Getty | Matt Anderson Photography)
Solar eclipse August 21, 2017 at 1:15 pm from Wisconsin, USA 85% Coverage (Image Source: Getty | Matt Anderson Photography)

This event is part of the Saros cycle, a recurring celestial pattern that spans approximately 18 years and 11 days. Astronomers meticulously calculate the magnitude of each eclipse, which indicates the fraction of the sun’s diameter that will be blocked. While this specific event is a partial eclipse, others in the same Saros series can be total, annular, or a rare hybrid. This particular eclipse will be visible in parts of the Pacific Ocean, New Zealand, and Antarctica.

Eclipses from Saros 136: 1937 through 2081 (Image Source: NASA | Michael Zeiler)
Eclipses from Saros 136: 1937 through 2081 (Image Source: NASA | Michael Zeiler)

The upcoming eclipse will be visible across a wide expanse of the Southern Hemisphere. Observers in New Zealand, Australia, Fiji, and Tonga are in for a prime opportunity to witness the event. The partial eclipse will also be visible from American Samoa, the Cook Islands, French Polynesia, Kiribati, and other Pacific islands, including Tokelau, Tuvalu, and Wallis and Futuna. Additionally, regions in Antarctica and the Solomon Islands, Vanuatu, and New Caledonia will experience a partial view of the celestial spectacle.

More on Starlust

2025 partial solar eclipse: When and how to watch the astronomical phenomenon on September 21

In a breakthrough, scientists successfully predicted a solar storm just 15 hours before it struck Earth

MORE STORIES

A long-overdue solar blast struck, delivering a powerful hit to Earth and the newly discovered Comet Lemmon (C/2025 A6), causing a dramatic, though temporary, separation of the comet's tail.
16 hours ago
Researchers at the University of York now propose that the elusive substance could leave a subtle, detectable red or blue 'fingerprint' on light.
1 day ago
Researchers led by a team at MIT identified a unique chemical signature in ancient rocks pulled from deep within the Earth, including samples from Greenland, Canada, and the Hawaiian mantle.
2 days ago
Led by the Curtin University-based ICRAR, an international team of astronomers has ruled out a 'cold start' for the Epoch of Reionisation, a crucial, little-explored era in cosmic history.
5 days ago
Discovered by ATLAS in July 2025, the interstellar comet 3I/ATLAS is only the third such visitor ever observed in our solar system.
5 days ago
By compiling signals from the Einstein Probe and the Russian Konus-Wind spectrometer, scientists verified the unprecedented phenomenon.
6 days ago
International astronomers used the Allen Telescope Array (ATA) to detect a rapid, powerful surge of radio waves signaling the destruction of a star.
6 days ago
A re-analysis of data from the defunct Cassini probe confirms the moon's subsurface ocean is more chemically rich than previously thought.
7 days ago
According to preliminary analysis, the newly identified exoplanet TOI-4507 b is challenging fundamental theories governing how celestial bodies evolve.
7 days ago
A new academic investigation suggests that previously unrecognized observations of the significant galactic supernovae SN 1006 and SN 1181 may be preserved within ancient Arabic writings.
7 days ago