Test 1 Flashcards
What are constellations?
Groups of stars relatively close together in the sky.
Where on Earth can you stand and, over the course of a year, see the entire sky?
The equator.
Why do we only ever see the same side of the Moon?
The moon rotates once each orbit. Also known as tidal lock.
When the moon is at the Meridian at sunrise, it’s phase is what?
Third quarter.
If you see the first quarter moon on the Meridian, the sun is in what direction?
On the western horizon.
If people on earth were looking at a total lunar eclipse, what would you see from the moon?
A totally dark earth.
The cities of Beijing and Philadelphia have about the same latitude, how does their view of the sky compare?
They’re identical.
What star does the Earth’s axis point toward?
Polaris
What direction does the moon rise in?
The east.
What is the term for the a planet appearing to travel backwards as the Earth catches up to it?
Retrograde motion.
What are inferior planets?
Any that are closer to the Sun.
What are superior planets?
Any that are farther from the Sun.
Describe the speeds of planets with elliptical orbits.
They slow when they travel away from their star and speed up when moving towards it.
Describe Kepler’s second law.
A planet will move fastest when it is closest to it’s star.
What is one of the first public criticisms of the geocentric model?
Galileo’s observations of the phases of Venus and of moons orbiting Jupiter, indicating not all things orbit Earth.
Define eccentricity.
The stretch of a planet’s elliptical orbit.
Why are high eccentricity planets unlikely to support life?
The changing distance from the star drastically changes the temperature.
Which of Newton’s laws explains why people continue moving when a car stops.
Inertia.
Why do we wear seatbelts in cars and airplanes?
To protect against acceleration.
How would the speed of a satellite moving to a different orbiting altitude change?
Lower: faster, higher: slower
The connection between gravity and orbits enables astronomers to measure a planet’s what?
Mass.
How does the gravitational force change based on distance?
It is an inverse square. So a moon half as far would experience 4 times the force, while a moon twice as far would experience a fourth of the force.
Describe where the moon is during spring(vernal) and neap tides.
During spring tides it is in line with the Earth and the Sun, while during neap tides they form a right angle.
Self gravity is what?
The gravitational effect of all parts of a body.
