| |
igneous rock
rock formed by the solidification of magma
|
inclination
the angle between a planet’s orbit and the ecliptic plane; or the angle between a satellite’s orbit and its host planet’s rotational plane
|
inferior conjunction
the configuration of an inferior planet when it lies between the sun and Earth
|
inferior planet
a planet that orbits the sun inside of Earth’s orbit; includes Mercury and Venus
|
inflation
a brief and extraordinarily rapid period of expansion a fraction of a second after the Big Bang
|
infrared
a form of light with slightly lower energy than visible light but with greater energy than radio waves
|
interacting galaxies
galaxies caught in each other’s gravitational embrace, often results in galactic mergers or extreme star formation
|
interference fringes
a wave-like pattern resulting from the successful combination of two beams of light which amplifies the light
|
interferometer
a system of two or more widely separated telescopes that achieves the resolving power of a much larger telescope
|
interferometric fringes
a wave-like pattern resulting from the successful combination of two beams of light which amplifies the light
|
interferometry
the technique of using two or more widely separated telescopes to achieve the resolving power of a much larger telescope
|
intergalactic
the space between the galaxies
|
interplanetary
the space between the planets
|
interstellar
the space between the stars of a galaxy
|
interstellar medium
the gas and dust located between the stars
|
ion
an atom that is electrically charged due to the loss or gain of one or more electrons
|
ionization
the process by which an atom gains or loses electrons
|
ionized gas
a gas that has been heated to a state where it contains ions and free-floating electrons; also known as a plasma
|
ionosphere
an atmospheric layer with a high concentration of ions and free electrons
|
irregular galaxy
a galaxy without a clearly defined spiral or elliptical shape
|
isotope
forms of an element in which the atoms all have the same number of protons but different numbers of neutrons
|