Why are the Northern Lights so intense lately and how long will it last?

Most flares (classes A, B and C) are barely distinguishable from the rest of the solar activity taking place around them. However, the strongest… Class M And Class Flares – appear at orbiting telescopes like NASA’s Solar Dynamics Observatory as bright bursts of light. They can also pose a risk to astronauts orbiting spacecraft and tend to saturate the ionosphere on Earth’s dayside, disrupting long-range radio transmissions and GPS signals from satellites.

The massive “prominence” shown on the left emerged from the Sun on August 31, 2012, forming the CME shown on the right as it moved away from the Sun. (NASA SDO, NASA/NOAA SOHO)

A coronal mass ejection Typically occurs during a solar flare, when new connections made between the magnetic fields around a sunspot cause a section of one of the magnetic loops to shear and eject. The resulting rash, sometimes called solar stormbecomes a massive cloud of charged solar particles, energized and accelerated by the flare, and carrying with it a “piece” of the Sun’s magnetic field as it expands outward into space.

If a CME passes beyond Earth, it can potentially cause a geomagnetic storm and auroras. Its impact, however, depends on conditions within the cloud.

What causes the brightest and most widespread auroras?

Auroras are caused by solar particles, usually electrons, plunging into Earth’s upper atmosphere. There, they release the oxygen and nitrogen present in the air and thus transmit their energy. Oxygen and nitrogen then release this energy as flashes of colored light, with oxygen producing green and red light (the two most common colors) and nitrogen typically emitting blue and violet. Different colors of light can blend into other hues like yellow, orange, and pink.

As mentioned above, a coronal mass ejection is a cloud of solar particles that erupts from the Sun, usually following a solar flare. The cloud has a certain density (the amount of particles it contains), the particles it contains have a certain temperature (the energy they have absorbed from the Sun and the solar flare) and the cloud is moving at a certain speed. Since the cloud is made up of moving charged particles, it also carries electric and magnetic fields.

This diagram shows the interaction between the magnetic field of a CME and the Earth’s geomagnetic field, where a CME with a positive field direction is repelled (top example) and a CME with a negative field direction is attracted (top example). down). (Javalab/Scott Sutherland)

LEARN MORE: How do the Northern Lights shine? Here’s the science behind the aurora

Under normal conditions, particles captured by the solar wind follow the outermost “layer” of the Earth’s magnetic field into the atmosphere. Thus, they only flock near the poles and the auroras that form are confined to these same regions.