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Which of the choices below correctly lists things in order from largest to smallest?
Universe, Local Group, Milky Way, Solar System
Aristotle hypothesis was that:
only a spherical Earth would always cast a circular shadow on the Moon.
In general, what is true of the alpha star in a constellation?
It is the brightest star in the constellation.
While watching a star, you see it moves 15 degrees across the sky. How long have you been watching it?
Which statement about the ecliptic is FALSE?
The Moon can never leave it, but moves twelve times faster than the Sun.
You note that a particular star is directly overhead. It will be directly overhead again in
23 hours 56 minutes.
When is the Sun located at 6 hours RA, -23.5 degrees declination?
Sun is never found at this position.
The Ptolemaic model of the universe:
explained and predicted the motions of the planets with deferents and epicycles.
Scientists today do not accept the Ptolemaic model because:
the work of Tycho and Kepler showed the heliocentric model was more accurate.
According to Copernicus, the retrograde motion for Mars must occur
at opposition, when the earth overtakes Mars and passes between Mars and the Sun.
Which was a contribution to astronomy made by Copernicus?
He laid out the order and relative motion of the known solar system.
A fatal flaw with Ptolemy's model is its inability to predict the observed phases of
Mercury and Venus.
Kepler's first law worked, where Copernicus' original heliocentric model failed, because Kepler described the orbits as
elliptical, not circular.
Tycho Brahe's contribution to Kepler's Laws of Planetary Motion were
his detailed and accurate observations of the planet's position.
Upon which point do Copernicus and Kepler disagree?
The orbits of the planets are ellipses, with one focus at the Sun.
Which concept was NOT a part of Kepler's Laws of Planetary Motion?
Epicycles are needed to explain the varying brightnesses of the planets.
What does Kepler's third law imply about planetary motion?
Planets further from the Sun orbit at a slower speed than planets closer to the Sun.
A planet whose distance from the Sun is 3 A.U. would have an orbital period of how many Earth-years?
square root 27
The force of gravity between two objects:
increases with the masses of the bodies, but decreases with the square of the distances between them.
According to Newton's Law of Universal Gravitation, if the Moon were three times further from Earth, the force by Earth on the Moon would
decrease by a factor of 9.
If the distance between two asteroids is doubled, the gravitational force they exert on each other will
be one fourth as great.
Orbital speed is the speed with which a planet moves around the Sun. This speed is determined by
the mass of both the planet and the Sun and the distance between the two.
According to Copernicus, retrograde motion for Venus must occur around
inferior conjunction, when it passes between us and the Sun.
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