Vocab Flashcards
Orbit
The circular or elliptical path of an object as it revolves around another object.
Solar System
A system of objects that revolve around a star.
Galaxy
A group of solar systems, dust, and gas held together by gravity; our solar system is part of the Milky Way galaxy.
Universe
Everything that exists in, on and around the Earth
Satellite
A natural or artificial object that revolves around another object in space.
Impact Crater
An approximately circular depression in the surface of a planet, moon, or other solid body in the Solar System or elsewhere, formed by the hypervelocity impact of a smaller body
Rotation
The spinning of a celestial body, such as a planet, around an axis.
Revolution
The orbiting of an object around another object.
Season
a period of the year determined by the position of Earth as it revolves around the sun
Equinox
the twice-a-year occurrence during which Earth’s axis is perpendicular (at a 90 angle) to a line joining the Sun and Earth’s center
solstice
the twice-a-year occurrence during which the Sun appears at the highest point in the sky as seen from the North or South pole
Lunar Mare
The lunar maria are large, dark, basaltic plains on Earth’s Moon, formed by ancient volcanic eruptions. They were dubbed maria, Latin for “seas”, by early astronomers who mistook them for actual seas.
Eclipse
an event whereby one astronomical body passes between two other astronomical bodies
Umbra
the dark central part of a sunspot.
Penumbra
the less dark outer part of a sunspot, surrounding the dark core.
Origin
Astronomical Unit
a unit of distance equivalent to the average distance from Earth to the Sun: 149,598,000 kilometers; abbreviated “AU”
Ellipse
a regular oval shape, traced by a point moving in a plane so that the sum of its distances from two other points (the foci) is constant, or resulting when a cone is cut by an oblique plane which does not intersect the base.
Terrestrial Planet
Within the Solar System, the terrestrial planets are the inner planets closest to the Sun, i.e. Mercury, Venus, Earth, and Mars. The terms “terrestrial planet” and “telluric planet” are derived from Latin words for Earth (Terra and Tellus), as these planets are, in terms of structure, Earth-like.
Gas Giant
a large planet of relatively low density consisting predominantly of hydrogen and helium, such as Jupiter, Saturn, Uranus, or Neptune.
Asteroid
a small object made of rock or metal that orbits the sun
Comet
a body of ice and dust that travels in a long narrow orbit around the sun
Meteor
a streak of light in the sky that forms when a piece of rock from space burns up in Earth’s atmosphere
Meteorite
a piece of rock or metal from space that strikes Earth’s surface
Geocentric
having the Earth as the center
Heliocentric
having the sun as the center
Gravity
a force that exists between any two objects that have mass
Tide
the regular fluctuation of sea water driven by the gravitational pull of the Moon and Sun on Earth’s oceans and other large bodies of water
Waxing
Waxing is “Maxing,” or growing with light until a full moon is reached. Waning is the opposite, or decreasing after a full moon, and is always illuminated on the left. Then, there is a waxing or waning Gibbous moon, which means more than half of the moon is illuminated.
Waning
Waning is the opposite, or decreasing after a full moon, and is always illuminated on the left. Then, there is a waxing or waning Gibbous moon, which means more than half of the moon is illuminated. And then a waxing or waning Crescent Moon, when less than half is illuminated.
Gibbous Moon
Just after the First Quarter Moon, when we can see exactly half of the face of the Moon illuminated, the intermediate phase called Waxing Gibbous Moon starts. … Gibbous refers to the shape, which is less than the full circle of a Full Moon, but larger than the semicircle shape of the Moon at Third Quarter.
Crescent Moon
The Moon as it appears early in its first quarter or late in its last quarter, when only a small arc-shaped section of the visible portion is illuminated by the Sun.
Full moon
The full moon is the lunar phase when the Moon appears fully illuminated from Earth’s perspective. This occurs when Earth is located between the Sun and the Moon. This means that the lunar hemisphere facing Earth – the near side – is completely sunlit and appears as a circular disk
Quarter Moon
A quarter moon occurs when we see the Moon half illuminated by the Sun, and half enshrouded in darkness. Since the illuminated side points towards the Sun, it tells astronomers that the Moon and the Sun are separated by 90-degrees from our perspective here on Earth.
Perihelion
DescriptionApsis denotes either of the two extreme points in the orbit of a planetary body about its primary body. The plural term, “apsides,” usually implies both apsis points; apsides can also refer to the distance of the extreme range of an object orbiting a host body.
Aphelion
Apsis denotes either of the two extreme points in the orbit of a planetary body about its primary body. The plural term, “apsides,” usually implies both apsis points; apsides can also refer to the distance of the extreme range of an object orbiting a host body
