Astronomy 1010 (Quiz 1 & 2)
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.
Into how many constellations is the celestial sphere divided?
What are constellations?
Groups of stars making an apparent pattern in the celestial sphere
Where on Earth can you observe all the stars in the sky over an entire year?
In general, what is true of the alpha star in a constellation?
It is the brightest star in the constellation.
What is the range of values for declination?
+90 to -90 degrees
While watching a star, you see it moves 15 degrees across the sky. How long have you been watching it?
Which statement about declination is FALSE?
It is measured eastward in units of time.
A star with a right ascension of 1.0 hours will rise
1.0 hour after the vernal equinox.
The place the Sun stops its northward motion along the ecliptic is the:
The places where the Sun crosses the equator are called the:
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.
That Polaris will not always be the pole star is due to
precession shifting the celestial pole.
What celestial line is a product of the Earth's orbit around the Sun?
When is the Sun located at 6 hours RA, -23.5 degrees declination?
Sun is never found at this position.
A solar eclipse can only happen during a:
A lunar eclipse can only happen during a:
If you are in the Moon's umbral shadow, then you will witness
a total solar eclipse.
If new Moon fell on March 2nd, what is the Moon's phase on March 14th?
What conditions are necessary for an annular solar eclipse?
new moon on ecliptic at apogee
What conditions are necessary for a total solar eclipse?
new moon on ecliptic near perigee
When the Moon is directly opposite the Sun in the sky, its phase is
A star with a large parallax
is at a short distance from Earth.
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.
When a planet retrogrades, it appears to move westward for weeks at a time.
On which of these assumptions do Ptolemy and Copernicus agree?
All orbits must be perfect circles.
The heliocentric model was actually first proposed by:
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.
Which of these was NOT seen telescopically by Galileo?
Which of these was NOT a telescopic discovery of Galileo?
the moons of Saturn
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.
A circular orbit would have an eccentricity of
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 Law of Universal Gravitation was developed by:
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.
Escape velocity is the speed required to
overcome the graviational pull of an object.
According to Copernicus, retrograde motion for Venus must occur around
inferior conjunction, when it passes between us and the Sun.
Kepler's second law implies what about planetary motion?
A planet moves faster when it is closer to the Sun.