Coronal Mass Ejections

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A massive burst of plasma and magnetic field from the Sun's corona that can cause geomagnetic storms on Earth.

What is a coronal mass ejection (CME)?

"A coronal mass ejection (CME) is a significant ejection of magnetic field and accompanying plasma mass from the Sun's corona into the heliosphere."

What are CMEs often associated with?

"CMEs are often associated with solar flares and other forms of solar activity."

Is there a widely accepted theoretical understanding of the relationship between CMEs and solar flares?

"But a broadly accepted theoretical understanding of these relationships has not been established."

What happens when a CME enters interplanetary space?

"If a CME enters interplanetary space, it is referred to as an interplanetary coronal mass ejection (ICME)."

What can ICMEs do when they collide with Earth's magnetosphere?

"ICMEs are capable of reaching and colliding with Earth's magnetosphere, where they can cause geomagnetic storms, aurorae, and in rare cases damage to electrical power grids."

What was the largest recorded geomagnetic perturbation presumably caused by a CME?

"The largest recorded geomagnetic perturbation, resulting presumably from a CME, was the solar storm of 1859."

What was the impact of the solar storm of 1859 (Carrington Event)?

"It disabled parts of the newly created United States telegraph network, starting fires and shocking some telegraph operators."

How often does the Sun produce CMEs near solar maxima?

"Near solar maxima, the Sun produces about three CMEs every day."

How often does the Sun produce CMEs near solar minima?

"Near solar minima, there is about one CME every five days."

What is the source of a CME?

"A coronal mass ejection (CME) is a significant ejection of magnetic field and accompanying plasma mass from the Sun's corona..."

What can cause geomagnetic storms and aurorae on Earth?

"ICMEs are capable of reaching and colliding with Earth's magnetosphere, where they can cause geomagnetic storms and aurorae."

How did the solar storm of 1859 affect the United States telegraph network?

"[It] disabled parts of the newly created United States telegraph network, starting fires and shocking some telegraph operators."

What is the term used for a CME that enters interplanetary space?

"If a CME enters interplanetary space, it is referred to as an interplanetary coronal mass ejection (ICME)."

Is there a specific event associated with the largest recorded geomagnetic perturbation caused by a CME?

"The largest recorded geomagnetic perturbation, resulting presumably from a CME, was the solar storm of 1859. Also known as the Carrington Event..."

What is the potential consequence of ICMEs colliding with Earth's magnetosphere?

"...where they can cause geomagnetic storms, aurorae, and in rare cases damage to electrical power grids."

How frequently does the Sun produce CMEs near solar maxima?

"Near solar maxima, the Sun produces about three CMEs every day."

How frequently does the Sun produce CMEs near solar minima?

"Near solar minima, there is about one CME every five days."

What can CMEs cause on Earth in rare cases?

"...in rare cases damage to electrical power grids."

Are CMEs only associated with solar flares?

"CMEs are often associated with solar flares and other forms of solar activity."

Is there a clear understanding of the relationship between CMEs and solar flares?

"But a broadly accepted theoretical understanding of these relationships has not been established."