Vocabulary We Might Need to Know

Carrington Event (1859) - the largest solar storm on record, which included a megaflare strong enough to produce aurorae as far south as Cuba and Hawaii and reportedly caused sparks from telegraph equipment.

ecliptic - the apparent path of the Sun across the sky relative to the stars as seen from Earth; also used to describe (roughly) the plane of the solar system that includes the orbits of most of the planets.

ESA - European Space Agency, a multinational space program headquartered in Paris and operating out of Guyana.

gamma-ray bursts (GRB) - highly energetic flashes of point-source gamma rays observed in other galaxies; discovered accidentally by military satellites monitoring Earth-based nuclear weapons testing. Among the most powerful events in the known universe, their origin is still poorly understood.

heliosphere - the bubble in the interstellar medium created by the solar wind, which includes the Sun and the entire solar system.

JAXA - Japan Aerospace Exploration Agency, Japan's national space program, headquartered in Tokyo.

Lagrangian points - the five points in orbital configuration between the Sun and Earth (L1-L5) where gravitational forces equal centripetal forces, thereby providing a stable orbiting point for satellites relative to the larger bodies.

magnetar - a special type of neutron star with an extremely powerful magnetic field and an extremely fast period of rotation.

occultation - the interruption of the light from a celestial body or of the signals from a spacecraft by the intervention of a celestial body; especially, an eclipse of a star or planet by the moon.

panspermia - the theory that life originated on Earth as a result of biological seeding by meteorites and comets.

perigee - the point of closest approach by an object or satellite orbiting a larger body.

precession - the gravity-induced, slow and continuous change in the orientation of an astronomical body's rotational axis; namely, the shift in the orientation of a planet's axis as it traces out a cone-shaped cycle over many thousands of years.

sungrazers - relatively tiny comets whose orbits take them close to the Sun's surface, where they often vaporize soon after discovery

sun-synchronous orbit - a geocentric orbit that combines altitude, inclination and precession in such a way that an object always faces the Sun even as the Earth rotates beneath it