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48 Cards in this Set

  • Front
  • Back
List the planets, by distance from the Sun
Mercury, Venue, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
What is the largest dwarf planet
Name the dwarf planets
Ceres, Pluto, Eris
A body orbiting a planet.
A massive, gaseous body held together by gravity and generally emitting light.
Solar System
The Sun, planets, their moons, and other bodies, such as meteors and comets.
Astronomical Unit
A distance unit based on the average distance of the Earth from the Sun.
Big Bang
The event that began the universe.
Local Group
The small group of three spiral galaxies and several dozen small galaxies, to which the milky way belongs.
dark energy
A form of energy detected by its effect on the expansion of the universe.
Milky Way Galaxy
The galaxy to which the sun belongs.
dark matter
Matter that emits no detectable radiation but whose presence can be deduced by its gravitational attraction on other bodies.
A massive system of stars, gas, and dark matter held together by their mutual gravity.
galaxy cluster
A set of hundreds or thousands of galaxies held together by their mutual gravitational attraction.
galaxy group
A system of from two to several dozen galaxies held together by their mutual gravitational attraction.
A unit of distance equal to the distance light travels in one year.
stellar evolution
The gravity-driven changes in stars as they are born, age, and finally run out of fuel.
A cluster of galaxy groups and clusters.
The largest astronomical structure we know of.
Virgo Cluster
The nearest large galaxy cluster.
The line separating the sky from the ground.
MKS system
The form of the metric system using meters, kilograms, and seconds to measure length, mass, and time.
A unit of distance equal to about 3.26 light-years.
An easily identifiable grouping of stars, sometimes a part of a larger constellation.
celestial equator
An imaginary line on the celestial sphere lying exactly above the Earth's equator.
celestial pole
An imaginary point on the sky directly above the Earth's North, or South Pole.
celestial sphere
An imaginary sphere surrounding the Earth.
Close enough to a celestial pole that always remains above the horizon.
An officially recognized grouping of stars in the night sky.
declination (dec)
One part of a coordinate system for locating objects in the sky. North/South
the point on the celestial sphere directly below the observer.
A moderately bright star in the constellation Ursa Minor. The north star.
right ascension (RA)
Used to locate objects in the sky. East-West
The point on the celestial sphere that lies directly above the observer.
rotation axis
An imaginary line through the center of a body about which the body spins.
The beginning of winter and summer. The solstice occurs when the sun is at its greatest distance north or south.
Tropic of Cancer
The latitude line of 23.5 degrees north, marking the distance farthest north where the Sun can pass directly overhead.
Tropic of Capricorn
The latitude line of 23.5 degrees south, marking the distance farthest south where the Sun can pass directly overhead.
vernal equinox
Spring in the Northern Hemisphere begins on the vernal equinox, which is on or near March 20.
The time it takes the Earth to complete its orbit around the Sun.
A set of 12 constellations along the ecliptic, in a band around the celestial sphere.
apparent noon
The time at which the sun crosses the meridian as seen from a particular location.
leap second
A time adjustment added every few years to clocks around the world to adjust them to account for Earth's slowing speed.
sidereal day
The length of time from the rising of a star until it next rises.
sidereal time
A system of time measurement referenced to the motion of stars.
solar day
The time interval from sunrise to the next sunrise.
tidal braking
The slowing of one body's rotation as a result of gravitational forces exerted on it by another body.
universal time
The time kept at Greenwich, England, at the Prime Meridian.