Astronomy Flashcards
(86 cards)
Define Astronomy.
The scientific Study of what exists beyond Earth.
Define Celestial Object.
Any object that exists in space.
Define the Universe.
Everything that exists, including all energy, matter, and space.
Define a Star.
A massive collection of gases held together by its own gravity and emitting huge amounts of energy.
Define Luminous.
Producing and giving off light; Shining.
Define a Planet.
A large, round celestial object that travels around a star.
Define Solar System.
The sun and all the objects that travel around it.
Define Satellite.
A celestial object that travels around a planet or dwarf planet.
Define Orbit.
The closed path of a Celestial object or Satellite as it travels around another Celestial object.
Define Galaxy.
A huge, rotating collection of gas, dust, and billions of stars, planets, and other celestial objects.
Define Electromagnetic (EM) Radiation.
Energy emitted from matter, consisting of electromagnetic wives that travel at the speed of light.
Define Electromagnetic (EM) Radiation.
The range of wavelengths of electromagnetic radiation, extending from radio waves to gamma rays, and including visible light.
Define Sunspots.
Dark Spots appearing on the sun’s surface that are cooler than the surrounding areas.
Define Solar Flare.
Gases and charged particles expelled above an active sunspot.
Define Solar Prominence.
Low-Energy gas eruptions from the surface of the Sun’s surface that extend thousands of kilometers into space.
Define Aurora Borealis.
A display of shifting colours in the northern sky caused by solar particles colliding with matter in Earth’s upper atmosphere.
Define Astronomical Unit.
Approximately 150 million kilometers; the average distance from the Earth to the Sun.
Define Dwarf Planets.
A celestial object that orbits the Sun and has a spherical shape but does not dominate its orbit.
Define Comet.
A chunk of ice and dust that travels in a very long orbit around the sun.
Define Orbital Radius.
The average distance between an object in the Solar System and the Sun.
Define Gravitational Force.
The force of attraction between all the masses in the universe.
Define Solstice.
An astronomical event that occurs two times each year, when the tilt of the Earth’s axis is most inclined toward or away from the Sun, causing the position of the Sun in the sky to appear to reach the northernmost or southernmost extreme.
Define equinox.
The time of year when the hours of daylight are equal to the hours of darkness.
Define precession.
The changing position of the Earth’s axis.

