UCSB Astro1 Midterm Exam |120
Complete Q’s and A’s
which ways do stars move - -east to west
- scientific method - -observation, logic, and skepticism
- hypothesis - -collection of ideas that seems to explain what is observed
- theory - -a body of related hypotheses that can be pieced together into a
self-consistent description of nature
- meteorites - -chemically distinct bits of interplanetary debris that
sometimes fall to our planets surface
- Celestial Sphere - -old model of the universe where the earth is at the
center and the sun, planets and stars rotate around it
- How did the celestial sphere rotate - -once a day east to west around the
earth
- What is Diurnal motion - -an apparent motion in the sky that repeats on a
daily basis, such as the rising and setting of stars
- If we project earth's north and south poles into space we obtain what - -
the north celestial pole and the south celestial pole
- Celestial equator - -divides the sky into northern and southern
hemispheres
- zenith - -the point in the sky directly overhead an observer
- circumpolar - -stars that never rise or set
- what causes the seasons - -the tilt of earth's axis of rotation
- why is summer warmer than winter - -because the sun is high in the
midday summer sky so a shaft of sunlight is concentrated onto a small area,
which heats the ground effectively and makes the days warm
- why is winter colder than summer - -because the sun is lower midday
during winter so the same shaft of sunlight is spread out over a larger area
, - equinox - -the point where the ecliptic and celestial equator intersect and
the sun appears for almost exactly 12 hours a day
- vernal equinox - -during spring where the sun is out for 12 hours
- autumnal equinox - -during fall where the sun is out for 12 hours
- Summer solstice - -the point of the ecliptic farthest north of the celestial
equator, where the sun is out for the longest time during the year
- winter solstice - -the point on the ecliptic when the sun is furthest south of
the celestial equator, where the sun is out for the shortest amount of the
time during the year
- ecliptic plane - -the plane in which the earth moves around the sun
- precession - -the orientation of the earth's axis of rotation changes slowly
- what causes precession - -the gravitational pull of the sun and moon on
earths equatorial bulge
- what is the angle of earths axis - -23 1/2 degrees
- apparent solar time - -based on the apparent motion of the sun along the
celestial equator, which produces the uniform mean solar day of 24hrs
- sidereal time - -based on the apparent motion of the celestial sphere
- ecliptic - -the path the sun takes around the earth in the celestial sphere
model
- lunar phases - -the appearance of the illuminated area of the moon as
seen from earth
- New moon - -when the moon is in the same direction in the sky as the sun
so it isn't seen at night
- waxing crescent moon - -the amount of the moon illuminated is only a
crescent but it is increasing in how much we see
- first quarter moon - -when half of the moon is illuminated and and
illumination is increasing
- waxing gibbous moon - -when only a crescent of the moon is not
illuminated and the illumination is increasing
Complete Q’s and A’s
which ways do stars move - -east to west
- scientific method - -observation, logic, and skepticism
- hypothesis - -collection of ideas that seems to explain what is observed
- theory - -a body of related hypotheses that can be pieced together into a
self-consistent description of nature
- meteorites - -chemically distinct bits of interplanetary debris that
sometimes fall to our planets surface
- Celestial Sphere - -old model of the universe where the earth is at the
center and the sun, planets and stars rotate around it
- How did the celestial sphere rotate - -once a day east to west around the
earth
- What is Diurnal motion - -an apparent motion in the sky that repeats on a
daily basis, such as the rising and setting of stars
- If we project earth's north and south poles into space we obtain what - -
the north celestial pole and the south celestial pole
- Celestial equator - -divides the sky into northern and southern
hemispheres
- zenith - -the point in the sky directly overhead an observer
- circumpolar - -stars that never rise or set
- what causes the seasons - -the tilt of earth's axis of rotation
- why is summer warmer than winter - -because the sun is high in the
midday summer sky so a shaft of sunlight is concentrated onto a small area,
which heats the ground effectively and makes the days warm
- why is winter colder than summer - -because the sun is lower midday
during winter so the same shaft of sunlight is spread out over a larger area
, - equinox - -the point where the ecliptic and celestial equator intersect and
the sun appears for almost exactly 12 hours a day
- vernal equinox - -during spring where the sun is out for 12 hours
- autumnal equinox - -during fall where the sun is out for 12 hours
- Summer solstice - -the point of the ecliptic farthest north of the celestial
equator, where the sun is out for the longest time during the year
- winter solstice - -the point on the ecliptic when the sun is furthest south of
the celestial equator, where the sun is out for the shortest amount of the
time during the year
- ecliptic plane - -the plane in which the earth moves around the sun
- precession - -the orientation of the earth's axis of rotation changes slowly
- what causes precession - -the gravitational pull of the sun and moon on
earths equatorial bulge
- what is the angle of earths axis - -23 1/2 degrees
- apparent solar time - -based on the apparent motion of the sun along the
celestial equator, which produces the uniform mean solar day of 24hrs
- sidereal time - -based on the apparent motion of the celestial sphere
- ecliptic - -the path the sun takes around the earth in the celestial sphere
model
- lunar phases - -the appearance of the illuminated area of the moon as
seen from earth
- New moon - -when the moon is in the same direction in the sky as the sun
so it isn't seen at night
- waxing crescent moon - -the amount of the moon illuminated is only a
crescent but it is increasing in how much we see
- first quarter moon - -when half of the moon is illuminated and and
illumination is increasing
- waxing gibbous moon - -when only a crescent of the moon is not
illuminated and the illumination is increasing
