Jackson

You step out of the vehicle, and the Arctic air hits you like a wall. The thermometer reads -22 degrees Fahrenheit, but with wind chill it feels closer to -40. Above you, green ribbons of light are already dancing across the sky. This is the moment you traveled thousands of miles for. But if you … Read more

Scientists forecast the aurora 15 to 45 minutes before it appears by measuring the solar wind and interplanetary magnetic field at a point upstream of Earth using specialized spacecraft like NOAA’s DSCOVR and NASA’s ACE satellite. These satellites sit at the L1 Lagrange point, roughly 1.5 million kilometers toward the Sun, where they sample charged … Read more

Stand under the northern lights in Norway on a clear winter night, and at that very moment, someone in Tasmania might be watching the southern lights dance across the same dark sky. These two displays are not separate coincidences. They are two halves of one connected event, and the reason why the aurora australis mirrors … Read more

The auroral oval is a ring-shaped band around each of Earth’s magnetic poles where aurora borealis and aurora australis are most frequently visible. When a geomagnetic storm hits, this oval expands equatorward, pushing aurora visibility to much lower latitudes than normal. At Kp 2, the oval sits near 65 to 72 degrees magnetic latitude, but … Read more

Auroras glow purple along their lower edge when high-energy electrons from the solar wind penetrate deep into Earth’s atmosphere, below about 60 miles (100 km) altitude, where they collide with molecular nitrogen (N2) and ionized nitrogen (N2+). These nitrogen molecules emit blue and violet light that our eyes perceive as a reddish-purple or pink glow … Read more

On , the Sun ejected more than a billion tons of charged plasma into space. Three days later, people as far south as Texas and Italy stood outside at midnight, photographing auroras they never expected to see from their backyards. That gap between eruption and light show is not a coincidence. It is the result … Read more

Stand under a dark Arctic sky during a strong auroral display, and you will almost certainly see the same color painting the heavens: green. Millions of photographs, centuries of folklore, and countless traveler stories all reinforce the same image. The northern lights glow green. But why? What is it about the physics of our atmosphere … Read more

I have stood under enough aurora-soaked skies to learn the same hard lesson every time: the sky alone is not the photograph. The most breathtaking green ribbons I have ever watched were boring on the back of my camera until something on the ground gave them a place to live. Learning how to compose an … Read more

When a solar storm slams into Earth, charged particles get funneled along our planet’s magnetic field lines toward both the North and South Poles at the same time, creating aurora borealis and aurora australis simultaneously. This happens because Earth’s magnetic field acts like a giant bar magnet with field lines connecting one pole to the … Read more

The solar wind drives changes in auroral brightness by carrying the Sun’s magnetic field into Earth’s magnetosphere, where magnetic reconnection transfers energy to trapped electrons that then plunge into the polar atmosphere and excite atoms of oxygen and nitrogen into emitting light. When solar wind speed increases and its embedded magnetic field turns southward, that … Read more