Space Weather

The continuous stream of charged particles — mostly protons and electrons — that flows outward from the Sun's corona at hundreds of kilometres per second, filling the Solar System and shaping planetary magnetospheres.

A sudden, intense burst of radiation from the Sun's surface, released when magnetic energy in the corona is explosively reconfigured. The X-rays arrive in minutes and can ionise Earth's upper atmosphere, causing radio blackouts.

An enormous eruption of magnetised plasma from the Sun's corona, launching billions of tonnes of material into space. When aimed at Earth, a CME can drive the largest geomagnetic storms one to three days later.

A temporary disturbance of Earth's magnetosphere, driven by the arrival of a fast solar wind or a coronal mass ejection. Strong storms can disrupt satellites, power grids, and navigation, and drive bright auroras.

The glow produced when energetic particles from the magnetosphere spiral down Earth's magnetic-field lines and excite gases in the upper atmosphere — the visible signature of space weather over the polar regions.

The region around a planet dominated by its magnetic field, which deflects the solar wind and traps charged particles. Earth's magnetosphere shields the surface from most space radiation.

The vast bubble of solar wind and magnetic field that surrounds the entire Solar System, carving out a cavity in the surrounding interstellar medium and shielding the planets from a fraction of the galactic cosmic rays.

The outer boundary of the heliosphere, where the outward pressure of the solar wind balances the pressure of the interstellar medium — the edge of the Sun's domain, crossed by the two Voyager spacecraft.