Astro1 (midterm) Exam |131
Question and Answers |100% Scores
Summer solstice - --Summer in the Northern hemisphere
-Sun is on the ecliptic at highest northern point from the celestial equator
-Sun is highest in the sky for North
-Sun is lowest in the sky for South
-North pole in continuous daylight
-South pole in continuous darkness
- Winter solstice - --Winter in the Northern hemisphere
-Sun is on ecliptic but south of the celestial equator
-Sun is highest in the sky for south
Sun is lowest in the sky for North
-South pole in continuous sunlight
- Diurnal motion - -Daily APPARENT motion of the stars/Sun due to our
rotation
- Equinox - -When the celestial and ecliptic equators intersect
- Sidereal year - -A little over a year.The time it takes for the Sun to return
to the same position in relation to the celestial sphere (the stars)
- Tropical year - -The time it takes for the Sun to return to the vernal
equinox (a bit shorter than the sidereal year)
-365.25 days (reason for leap year)
-Caused by precession!
- Precession - -Because of gravitational pull, the Earth's rotation changes
slight direction (think of a top spinning and changing direction slowly)
So the direction that the North pole does actually change, but it takes
thousands of years to go through a full cycle
- Where does the North Pole always point to (at least for now)? - -Polaris
(North Star)
- What are the 2 reasons for the seasons? - -THE TILT
1. Sunlight is more direct in the Summer
2. Days are longer in the Summer
, - When is the Sun highest in the sky in southern Australia? - -December
solstice (because seasons are switched for North and South, so the Sun is
highest (aka Summer) for the south in Winter
- On the Summer solstice where is the Sun at noon on the Tropic of Cancer?
- -Directly overhead!
- On the Winter solstice, where is the Sun at the Tropic of Capricorn at noon?
- -Directly overhead!
- What would happen to the seasons if the Earth's orbit around the Sun were
made a perfect circle but nothing else changed? - -The seasons would
remain pretty much the same as they are today
- What are reasons that the summer in the northern hemisphere occurs in
June, July, and August? - -1. The days are longer in the northern hemisphere
than the southern hemisphere
2. The sun is higher in the sky during the day in the northern hemisphere
3. Sunlight in the northern hemisphere strikes the Earth at an angle closer to
vertical (more direct angle)
- Why do day lengths differ at different locations on Earth? - -Because the
Sun rises and sets at different times at different latitudes. it will stay daytime
much longer (always) during Summer in the Arctic Circle, and stay dark all
day/longer in the Arctic circle during Winter
- Arclength equation - -s = (angle) (distance=r)
To get it in degrees, multiply by pi/360
- The Sun will set in about an hour. You look up in the sky in the direction
that your shadow is pointing, and a little less than halfway up in the sky you
see the moon. What's its shape? - -Gibbous (more than half the moon but
not all of it)
- You go outside at midnight and see a quarter moon. Where is it in the sky?
- -Near the horizon
- What causes tides? - -The Moon's gravitational pull causes a tidal bulge on
the side nearest to the Moon and furthest from the Moon
- You are living at a moon base and watch the motions of the Earth and Sun
in the lunar sky. What would you see? - -The Earth wouldn't appear to move
Question and Answers |100% Scores
Summer solstice - --Summer in the Northern hemisphere
-Sun is on the ecliptic at highest northern point from the celestial equator
-Sun is highest in the sky for North
-Sun is lowest in the sky for South
-North pole in continuous daylight
-South pole in continuous darkness
- Winter solstice - --Winter in the Northern hemisphere
-Sun is on ecliptic but south of the celestial equator
-Sun is highest in the sky for south
Sun is lowest in the sky for North
-South pole in continuous sunlight
- Diurnal motion - -Daily APPARENT motion of the stars/Sun due to our
rotation
- Equinox - -When the celestial and ecliptic equators intersect
- Sidereal year - -A little over a year.The time it takes for the Sun to return
to the same position in relation to the celestial sphere (the stars)
- Tropical year - -The time it takes for the Sun to return to the vernal
equinox (a bit shorter than the sidereal year)
-365.25 days (reason for leap year)
-Caused by precession!
- Precession - -Because of gravitational pull, the Earth's rotation changes
slight direction (think of a top spinning and changing direction slowly)
So the direction that the North pole does actually change, but it takes
thousands of years to go through a full cycle
- Where does the North Pole always point to (at least for now)? - -Polaris
(North Star)
- What are the 2 reasons for the seasons? - -THE TILT
1. Sunlight is more direct in the Summer
2. Days are longer in the Summer
, - When is the Sun highest in the sky in southern Australia? - -December
solstice (because seasons are switched for North and South, so the Sun is
highest (aka Summer) for the south in Winter
- On the Summer solstice where is the Sun at noon on the Tropic of Cancer?
- -Directly overhead!
- On the Winter solstice, where is the Sun at the Tropic of Capricorn at noon?
- -Directly overhead!
- What would happen to the seasons if the Earth's orbit around the Sun were
made a perfect circle but nothing else changed? - -The seasons would
remain pretty much the same as they are today
- What are reasons that the summer in the northern hemisphere occurs in
June, July, and August? - -1. The days are longer in the northern hemisphere
than the southern hemisphere
2. The sun is higher in the sky during the day in the northern hemisphere
3. Sunlight in the northern hemisphere strikes the Earth at an angle closer to
vertical (more direct angle)
- Why do day lengths differ at different locations on Earth? - -Because the
Sun rises and sets at different times at different latitudes. it will stay daytime
much longer (always) during Summer in the Arctic Circle, and stay dark all
day/longer in the Arctic circle during Winter
- Arclength equation - -s = (angle) (distance=r)
To get it in degrees, multiply by pi/360
- The Sun will set in about an hour. You look up in the sky in the direction
that your shadow is pointing, and a little less than halfway up in the sky you
see the moon. What's its shape? - -Gibbous (more than half the moon but
not all of it)
- You go outside at midnight and see a quarter moon. Where is it in the sky?
- -Near the horizon
- What causes tides? - -The Moon's gravitational pull causes a tidal bulge on
the side nearest to the Moon and furthest from the Moon
- You are living at a moon base and watch the motions of the Earth and Sun
in the lunar sky. What would you see? - -The Earth wouldn't appear to move
