14 terms

Beyond Earth Vocabulary

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solar eclipse
Order: Sun, Moon, Earth; moon's shadow falls on Earth; happens on the day side of Earth.
lunar eclipse
Order: Sun, Earth, Moon; Earth's shadow falls on the Moon, happens on the night side of Earth
Ellipse
geometric shape of orbits; its like an oval
Focus (foci, plural)
locations near the middle of the ellipse; the Sun is located at one focus
Eccentricity
A mathematical calculation that describes how "oval-ish" an ellipse is. Eccentricity = 0 means the ellipse is a perfect circle.
Perigee
the point in which the Moon is closest to Earth in its orbit
Apogee
the point in which the Moon is farthest from Earth in its orbit
Astronomical Unit (AU)
a unit of length measurement; its equal to the average distance between the Earth and the Sun
Gravitation
the most basic force in the universe; the more massive an object, the more gravity it has.
satellite
any object that orbits around another object
Inertia
a body at rest will remain at rest and a body in motion will remain in motion unless acted upon by an outside force.
nuclear fusion
process of lighter elements combining to form heavier atoms; Ex. Hydrogen atoms combine to form helium in a star's core
sunspots
areas on the Sun's surface that are lower temperature and appear darker
red-shift
the main piece of evidence that our universe is expanding; objects that are moving away from Earth create a red-shifted spectrum