When it is summer in Charlottesville, it is winter in Australia
true
The spring tides occur twice per year
false, they occur twice each lunar month
The acceleration of a planet that travels in a circular orbit without speeding up or slowing down is zero
false, acceleration is >0 for any kind of circular motion
The dark side of the moon is impossible to see from the earth because it is never illuminated by the Sun light
false, we can't see it because the moon's rotation and orbit result in us only seeing one side, the other side is illuminated during a new moon etc.
Viewed from the Earth's equator, the star Polaris appears at the zenith
false, it appears near the horizon
Viewed from the North pole of the Earth, when does the Sun rise to the zenith at noon?
never
An astronomer discovers an object at a distance of 28 million light years from the Earth is most likely
A galaxy
Earth-Sun Distance: 500 light seconds = 1AU
Solar System: 1/2 light days
Milky Way Galaxy: 100,000 light years
Observable Universe: 14 billion light years NOW
Kepler
1) discovered that the orbits of planets are ellipses
2) found that planets don't orbit at constant speed around the Sun
3) discovered the relationship between orbital period and the average distance of the planet from the sun
What phase is the moon if at 3 PM, half the surface is bright and half is dark?
First quarter
new moon: rise 6AM, set 6PM
first quarter: rise at noon, set at midnight
full moon: rise 6PM, set 6AM
third quarter: rise at midnight, set at noon
The number of stars typical in a galaxy like our Milky Way Galaxy is roughly
100 billion
Which is smallest: 1 light second, the diameter of earth, 1 AU, or the diameter of the Sun?
the diameter of earth
On the first day of winter in Charlottesville, what direction does the Sun set?
Southwest
Summer solstice: 6/21, Highest path, rise and set toward NORTH
Winter solstice: 12/21, Lowest path, rise and set toward SOUTH
Equinoxes: 3/21 & 9/21, rise and set at due eat and west
Why do we see different stars in different seasons?
As the Earth orbits the Sun we see the Sun in front of different constellations
If the radius of the Earth doubled (mass unchanged) the force of gravity would
decrease by a factor of 4 (Fg=G(m1m2/r^2))
When was the carbon we find on Earth produced?
inside stars before the formation of Earth
He & H formed during big bang, clump into stars, nuclear fusion in stars form carbon, oxygen, iron, etc
How does tidal friction affect the length of days and months?
both are getting shorter
Why are the Zodiac constellations special?
they mark the path of the Sun across the sky throughout the year
If you see the Moon setting during a total lunar eclipse, what time is it?
sunrise ***why?? tf
The moons of Jupiter were discovered by
Galileo
Are constellations in the southern hemisphere different from in the northern hemisphere?
yes
Who first established the earth as circular and measured its circumference?
the ancient greeks
Who was the first to explain tides?
Newton
A comet has a very eccentric orbit (~1) that is quite close to the sun at closest approach and beyond mars when farthest, with a semi-major axis at 1 AU. What is its orbital period and where does it spend most of its time?
One year, mostly beyond Earth's orbit
(greater eccentricity = less circular)
difference bw velocity and speed?
velocity has magnitude and direction
Who discovered the phases of venus?
Galileo
Newton's third law application to rockets
for every force there is an equal and opposite force, so rocket fuel burning creates force against front of rocket, opposite force downward toward the earth, force = ma so acceleration proportional to force
eclipses
lunar eclipse when Earth is between sun and moon, solar eclipse when moon is between sun and earth
There are 2 seasons for every eclipse year bc of the moon's tilted orbital plane (the ecliptic). "Lunar nodes" where the orbital planes of the sun and moon
The observable universe
it is the region of the universe that can be observed by earth now, 14 billion lys old, 7 billion lys @ half its age??
Venus evidence against ptolemaic model
its phases indicate it orbits the sun and not the earth
annular solar eclipse
they occur when the moon is farther away from the Earth when it reaches the node, and will become more frequent as the moon moves away from earth due to tidal friction