science Space Unit topic 1 Flashcards
(23 cards)
what does it mean for the sight of the dancing lights of the aurora borealis
spirits are dancing across the sky
what is a solstice
the longest and shortest day of the year depending by the suns position in the sky
what is equinox
one of the two points in earths orbit when the number of daylight hours are equel to the number to the numbers of hours of night
ancient people used these to track seasons
lunar cycles
stonehenge
chichen itza
khufu pyramid
what is the geocentric model
a earth centered model to explain planetary motion
what is the heliocentric model
1530 copernicus made observation that led him to conclude that the sun was at the center and the planets revolved around it
who discovered ellipses
johannes kepler
what was merkhet used for
to predicts star motion
what was the quadrant used for
to measure star altitude
what was the astrolabe used for
to chart star positions
what is the cross-staff used for
1300’s to measure the angle between the moon and stars
when was the first optical telescope made
1500
what is astronomical unit used for
used for local solar system disances
what are the star characteristics
size
density
temperature
brightness
what is a main sequence
where stars spend most pf their existence converting hydrogen to helium
how is a star made
gravity pulls gas and dust in a nebula together into a rotating sphere. the mass and temperature continuse to increase, at 10 millions celcius fusion begings converting hydrogen to helium
what is a constellation
grouping of stars we officially recognize as patterns in the night sky
what is a asterism
unofficially recognized star group
what is a galaxy
a group of millions or billions of stars gas and dust held together by gravity
what is a elliptical
a disk or football shaped galaxy made up of mstly old stars
what is a spiral
milky way style galaxies with long curved arms leading away from a bright central core
what is a irregular
small galaxy that lacks a definite shape
zenith
the highst point above head
