ASTR (TEST 1)

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Terms in this set (...)

Solar system
Consists of the sun, its family of planets, and some smaller bodies such as moons, asteroids, and comets.
Planets
Spherical, non-luminous bodies that orbit a star and shine by reflected light.
Dwarf planet
Pluto. Pluto meets some of the criteria of a planet, but is part of a larger group of small objects that circle the sun beyond Neptune.
Extrasolar planets
Very difficult to see because they are generally small, faint, and too close to the glare of their respective parent stars.
Galaxy
Great cloud of stars, gas, and dust held together by the combined gravity of all of its matter.
Field of view
The region you can see in an image, by a factor of 100.
Milky Way Galaxy
Home to the planet Earth.
Astronomical Unit
1 AU makes up the distance between the Earth and the Sun.
Constellations
Groups of stars named after celebrated heroes, gods, and mythical beasts - celebrated by native cultures.
Asterisms
Less formally defined groupings of stars. Ex. Big Dipper is a well-known asterism that is a part of the constellation Ursa Major.
Magnitude scale
A scale describing the brightness of stars.
Apparent visual magnitudes
Numbers describing a stars relative brightness as it relates to the vision capabilities of the human eye. Set to a scale of (-30) brightest to (30) faintest. The naked eye cannot see apparent magnitudes over the number (6)
Rotation
The turning of a body on its axis.
Revolution
The motion of a body around a point outside the body.
Ecliptic
The apparent path of the sun against the background of stars.
Pseudoscience
A set of beliefs that appears to include scientific ideas but fails to follow the most basic rules of science.
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A band around the sky extending about 9 degrees above and below the ecliptic, in which the sun, moon, and planets are always found.
Horoscope
A diagram showing the location of the sun, moon, and planets around the ecliptic and their position above or below the horizon for a given date and time.
Milankovitch hypothesis
States that small changes in the shape of earth's orbit and axis inclination, along with a subtle effect of precession, could combine to influence earth's climate and cause ice ages.
Umbra
The region of a total shadow.
Penumbra
In the penumbra, the sun is partly but not completely blocked.
Solar eclipse
Occurs when the moon moves between the earth and the sun.
Total solar eclipse
When the moon covers the disk of the sun completely.
Partial solar wxlipse
When the moon only partially covers the sun.
Apogee
In terms of moon: it's farthest point from the earth
Perigee
In terms of moon: its closest point to earth.
Annular eclipse
A solar eclipse in which a ring (or annulus) of light is visible around the disk of the moon.
Eclipse season
The period in which an eclipse occurs. Occurs when the sun is close to a node in the moon's orbit.
Saros cycle
After one saros, (8 years 11 & 1/3 days) the pattern of eclipses repeats.