As spring equinox nears, look for the northern lights: We explain why

There may be more northern lights – or aurora borealis – sightings this spring.

As we near the spring equinox, also known as the vernal equinox, on March 20, the Earth's magnetic field and solar wind align, creating an increased chance of seeing the colorful auroras in the Earth's upper atmosphere. According to Shannon Schmoll, director of the Abrams Planetarium recently told CNET, in the winter and summer months there's a lower chance because half the Earth is tilted away from the sun, known as the Russell-McPherron effect.

During the March and September equinoxes, the Earth's axis is parallel to the sun's. According to the Russell-McPherron effect, the magnetic fields of the Earth and the solar wind momentarily coincide, creating "cracks" that allow charged particles to accelerate and intensify the Earth's northern light displays.

The sun's solar cycle impact on northern lights

When the sun is "active," it produces more sunspots, which appear as black splotches on the face of the sun. The sun also produces powerful solar flares and coronal mass ejections that trigger geomagnetic storms, which lead to northern lights here on Earth.

This year's solar maximum is expected to be much stronger than the last one in 2014, which was uncharacteristically weak, said Allison Jaynes, associate professor of physics and astronomy at the University of Iowa.

The trend is expected to continue throughout 2025, Jaynes said. Solar maximum occurs when solar activity peaks within a specific solar cycle.

And that's great news for northern lights skywatchers.

Earth's magnetic field affected by the sun's solar flares

We are protected from the solar winds − streams of charged particles ejected from the sun − by an invisible barrier formed by Earth's magnetic field. Stronger solar winds can interfere with Earth's magnetic field. When the particle stream interacts with gases in the planet's magnetic field, stunning auroras are produced.

Atoms in air molecules in Earth's magnetic field are stimulated when charged electrons from the sun collide with them. As the molecules settle, they emit light. Green and red light are emitted by oxygen. The color of nitrogen is blue and purple.

You can find more northern light details on the Space Weather Prediction Center, which provides an aurora dashboard that should help skygazers track the phenomenon. And Aurorasaurus has a live map, with notification options.

CONTRIBUTING Victoria Reyna-Rodriguez/Paste BN NETWORK

SOURCE NASA, NASA's Goddard Space Flight Center, NASA’s Solar Dynamics Observatory, Smithsonian and Paste BN research