Astrophysics:
The branch of astronomy and physics that deals with the physics of astronomical objects.
Atmosphere:
The layer of gas surrounding the earth or other planets. The upper atmosphere is the region of Earth's atmosphere above the troposphere. Regions of the upper atmosphere are the stratosphere, mesosphere and thermosphere.
Aurora:
The bright emission of atoms and molecules in the polar upper atmosphere that appears as permanent, ring shaped belts called the auroral oval around the north and south geomagnetic poles. It is associated with a global electrical discharge process caused by energetic particles impinging on the upper atmosphere of Earth.
Auroral Oval:
The pattern of auroral light around the north and south magnetic poles.
Boundary layer:
The lowest layer of the Earth's atmosphere where the wind is influenced by the friction of the Earth's surface and the objects on it.
Comet:
A small body of ice and dust which orbits the Sun.
Corona:
The very hot outer layer of the Sun's atmosphere, composed of highly diffused, superheated, ionized gases, and extending into interplanetary space.
Coronal Mass Ejection:
A vast region of hot, dense, and high speed solar wind propagating away from the Sun.
Cosmic Rays:
Nuclear and subatomic particles moving through space at speeds close to the speed of light.
Energetic particles:
Electrically charged or fast moving particles
Energetic Photons:
eletrically charged or fast moving quantum of electromagnetic radiation.
Electromagnetic:
Relating to the interplay between electric and magnetic fields.
Electromagnetic Spectrum:
The array of electromagnetic radiation, arranged in order of wavelength.
Gamma Rays:
high energy, very short wavelength electromagnetic radiation which can be generated by nuclear reactions.
Geomagnetic Storm
Major disturbances of the magnetosphere that occur when the enterplanertary magneticfield turns southward and remains southward for a prolonged period of time.
Heliosphere:
The vast region starting at the Sun's surface and extending to the limits of the solar system.
Ion, Ionize:
ion is an atom which has lost or gained one or more electrons so that it has a net electrical charge.
Ionosphere:
The region of Earth's atmosphere that extends from about 50 to 300 miles above the surface of the planet and is made up of multiple layers dominated by electrically charged, or ionized, atoms.
Magnetic Field:
A field of force around the Sun and the planets, generated by electrical currents, in which a magnetic influence is felt by other currents.
Magnetopause:
The location in space where Earth's magnetic field balances the pressure of the solar wind. It is located about 63,000 km from Earth in the direction of the Sun, or about 1/6th the distance to the moon's orbit.
Magnetosphere:
the region of space above the atmosphere, and bounded by the magnetopause, that is under the direct influence of Earth's magnetic field.
Magnetosheath:
The region between the bow shock and the magnetopause, characterized by very turbulent plasma.
Magnetotail:
The region on the night side of the Earth where the magnetic field is stretched backwards by the force of the solar wind.
Photosphere:
The visible region of the sun: above the photosphere are the chromosphere, then the corona.
Plasma:
One of the four states of matter.
Plasma mantle:
the region covering the magnetosphere that extends toward the cusp region that contains de-energized magnetosheath plasma.
Plasma sheet:
a layer of weaker magnetic field and denser plasma that is centered on the equator and seperates the two tail lobes.
Plasmasphere:
A region of cold, dense plasma inside the magnetosphere that is populated by the outflow of ionospheric plasma along the magnetic field lines.
Polar Cusps:
Two funnel-shaped areas between the Sunward magnetic field and the tailward magnetic field where the solar wind enters and follows the magnetic field lines toward Earth.
Radiation Belt:
Zones that spiral around planets with charged particles interacting with the respective planets magnetosphere
Radiation:
Energy radiated in the forms of waves or particles.
Shock front (bow shock):
A collisionless shock wave in front of a planetary magnetosphere; the place where the supersonic flow of the solar wind is slowed to subsonic speed by the planetary magnetic field.
Solar Flare:
Eruptions of gas from the Sun's surface
Solar Wind:
Ejection of a gas from the Sun's surface
Space Weather:
The changing conditions in interplanetary space caused by fluctuations in the solar wind
Sunspot Cycle:
The cycle of the Sun when there are little sunspots (solar minimum) to where the are more sun spots (solar maximum)
Sunspot:
Darker and cooler regions of the sun where the magneticsphere loops out
Van Allen belts:
Two ring-shaped regions that girdle the Earth's equator in which electrically charged particles are trapped by the Earth's magnetic field