Coronal mass ejection

Definition

A Coronal Mass Ejection (CME) is a significant release of plasma and magnetic field from the Sun's corona into space. CMEs can impact space weather, potentially affecting satellites, astronauts, and power grids on Earth.

5 Must Know Facts For Your Next Test

1. CMEs are often associated with solar flares but can occur independently.
2. They can travel at speeds up to 3,000 kilometers per second.
3. CMEs are typically observed using coronagraphs on spacecraft like SOHO.
4. When directed towards Earth, CMEs can cause geomagnetic storms that disrupt communications and navigation systems.
5. The Sun emits CMEs more frequently during its solar maximum period.

Review Questions

• What are the potential effects of a CME on Earth's technology?
• How do scientists observe and study CMEs?
• Why are CMEs more common during the solar maximum?

Related terms

Solar Flare: A sudden flash of increased brightness on the Sun, often associated with magnetic activity.

Geomagnetic Storm: A disturbance in Earth's magnetosphere caused by solar wind or a CME interacting with Earth's magnetic field.

Coronagraph: An instrument that blocks out the direct light from a star so that nearby objects can be seen; essential for observing the Sun's corona.