ASTRONOMY 180 CH 1-4 EXAM
If it is 6:00 pm where you live and you see a full Moon, it is
"rising" from the eastern horizon.
If the Sun is directly in front of the zodiacal constellation Gemini right now at noon, how long would you have to wait to be able to see Gemini highest in the sky (on the meridian) at midnight?
6 months
At what time would you look to see a first-quarter moon at its highest position in the sky?
6 pm
Milky Way Galaxy, Local Group, Virgo Supercluster
8 hours.
A scientific theory is
A model explaining something that is backed by a large body of evidence and hasn't failed a single test.
The tilt of Earth's axis causes seasons by changing the
inclination of sunlight upon your location on Earth as the year progresses.
The time it takes a planet to make one complete orbit increases with the
increased distance from the Sun.
When we say that a satellite is orbiting a planet, we mean that the satellite
is falling freely around the planet.
If a satellite is orbiting Earth at constant speed,
its orbit is circular.
what is not a unit of length?
kilogram
Refraction can be described as
light bending as it passes through a different medium.
When the Moon is in a quarter phase, the
line connecting the Sun and Earth is at a right angle (90°) to the line connecting the Earth and the Moon.
When the Sun crosses the meridian at your location on Earth, it is
local noon.
x ray photons have _____ wavelengths than gamma ray photons
longer
The further north a star is, the _____ it stays up. Circumpolar stars that are near the north celestial pole _____ set
longer, never
Infrared light has _____ energy than ultraviolet.
lower
The "escape velocity" refers to the
lowest velocity required for an object to assume a path from which it never returns.
Red light has the ______ energy and frequency and the _______ wavelength.
lowest, longest
According to Newton's first law, a space probe traveling through interplanetary space will
maintain its motion without any outside force.
If a test of the prediction of a hypothesis supports that hypothesis, the next step in the scientific method is to
make and test more predictions of that hypothesis.
In order to improve the resolution of a telescope, we can
make its aperture larger.
A measurement of an object's inertia is made via its
mass.
Reflecting telescopes can be larger than refracting telescopes because
mirrors can be supported from the back but lenses must be supported from the sides.
If Earth's axis were tilted twice as much as it currently is, we would experience
more extreme seasons.
When using the scientific method, a hypothesis that would explain a particular observation
must be able to be tested.
1 x 10^-9 meters is a
nanometer
The ultimate tester of the correctness of scientific knowledge is
nature
The frequency of a wave is defined as the
number of wave crests passing a point in space each second.
Which of the following would make an idea falsifiable?
Tests can be designed that would show whether or not predictions made by the idea are correct.
A fingernail is closest in length to
1 cm.
Objects that are located on the celestial equator will be visible for only
12 hours per day
What will be the acceleration of a 40-kilogram object that is pushed with a net force of 80 newtons?
2 m/s2
384,000,000
3.84 x 10^8.
An asteroid has an average distance from the Sun of 3 AU. How long does it take to orbit once around the Sun?
5 years
Which of the following objects are not found inside our Solar System?
the Milky Way galaxy
The Moon is in synchronous rotation with Earth because
the Moon rotates on its axis once per revolution around Earth.
Compared to the winter, in the summer:
the Sun is higher in the sky at noon.
In the geocentric model,
the Sun, planets, and stars orbit Earth.
Galileo observed that Venus had phases, with the full phase occurring when Venus appeared smaller. This implied that
the heliocentric model of the Solar System was correct.
Keplars 3rd law states
the mass of a planet does not affect its orbital speed
A line running from due north to due south through a point directly overhead is called
the meridian.
Astronomical seeing is due to
the turbulent distortions of Earth's atmosphere.
Astronauts in orbit around Earth feel weightless because
they are falling around Earth.
Two objects of different weights are dropped simultaneously from the same height and land at the same time. This is because
they both have the same gravitational acceleration.
We get most of our knowledge about our universe
through telescope observations of light from astronomical objects.
It is advantageous for the Hubble Space Telescope (HST) to be in space while it observes astronomical objects in optical light
to avoid the distortion effects of Earth's atmosphere.
An ellipse has no more than
two foci.
An interferometer is
two or more telescopes acting as one instrument.
1 m/s into km/hr.
1000
There are 3.3 feet/meter. About how many meters are in 36 feet?
11
Earths rotation speed ____ AU
1
The resolution achievable by an unaided human eye is
1 arcminute.
How is an idea different from a hypothesis?
An idea can be anything, but a hypothesis is specifically an idea that leads to testable predictions.
Newton's first law states:
An object in motion tends to stay in motion in the same direction until an unbalanced force acts upon it.
Residents of the Southern Hemisphere cannot see the stars around the north celestial pole because
Earth itself is in the way.
In six months, you will be able to see a different set of stars in the night sky because
Earth will move.
Our complete cosmic address is
Earth, Solar System, Milky Way Galaxy, Local Group, Virgo Supercluster.
Where would you see the full moon when it starts to rise? What time would this happen?
Eastern horizon, rises at 6 pm
Where would you see the new moon, if it were visible, when it starts to rise?
Eastern horizon, starts at 6 am
How fast does light travel?
From Earth to the Moon in 1.25 seconds.
The first observational evidence that some objects in the sky did not orbit Earth was
Galileo's discovery that Jupiter's moons were near the planet.
What effect does high atmospheric seeing have on astronomical images?
It makes them more blurry.
What makes Kepler's laws empirical, but not Newton's laws?
Kepler's laws describe how things move based solely on observations, while Newton's laws give an underlying physical explanation for this motion.
Which of the following are in order from smallest to largest?
Milky Way Galaxy, Local Group, Virgo Supercluster
Sandy, a space shuttle astronaut, pushes on a bowling ball twice as hard as Doug, another space shuttle astronaut.
The acceleration of the ball that Sandy causes is twice as great as Doug's acceleration.
Which of the following is true?
The integration time of a photographic plate or CCD can be much longer than that of the human eye.
What is a major disadvantage of refractors?
The lens is subject to chromatic aberration.
From the perspective of a viewer in the Northern Hemisphere, which of the following is always true?
The north celestial pole is never somewhere overhead.
What causes the Moon to go through phases?
The relative positions of the Moon, Sun, and Earth as the Moon orbits Earth.
The speedometer of a car reads 30 mph (miles per hour). One minute later it reads 40 mph. Which of the following is true?
The speedometer is giving the car's speed at each moment, and the car is accelerating.
A crescent phase of the Moon can be seen at midnight if the Moon is
This situation is impossible; you cannot view this phase at this time.
What rays partially penetrate earths atmosphere and reach the surface?
UV & infrared by mountain-top observations
If the moon is a full moon tonight, will the moon be waxing or waning one week later? Which side of the moon (right or left) will appear illuminated at this time
Waning, LEFT
If it is 12 noon what moon phase would the earth observer see?
Waxing gibous
If the sun set below your western horizon about 2 hours ago, and the moon is barely visible on the eastern horizon, what phase would the moon be in at this time and location?
Waxing gibous
How do we test scientific knowledge?
We try to prove it wrong.
Where would you see the sun when the full moon starts to rise?
Western
Which of these ranges of electromagnetic radiation has the shortest wavelengths?
X-rays
Which of the following objects is accelerating?
a ball moving at a constant rate around a circular hoop
Centripetal force is
a force that always points toward the center of a circle.
The fact that light is quantized means that it can be thought of as
a particle.
Kepler's second law, the law of equal areas, states that
a planet moves its fastest when closest to the Sun.
From Earth to the Moon in 1.25 seconds.
about four years.
In the electromagnetic spectrum which light travels fastest?
all travel the same speed
Which of the following terms describes the event in which the Moon is directly centered over the disk of the Sun from the vantage point of Earth but is relatively far away from Earth in its orbit, so it is not large enough in our sky to cover the entire Sun?
an annular solar eclipse
Light can be generally described as
an electromagnetic wave that causes charged particles to vibrate.
In reality, the Celestial Sphere is
an imaginary surface on which distant objects appear to lie, which rotates because Earth is spinning on its axis.
Is there any location on Earth where the entire sky is potentially visible within a 24-hour period (ignoring the fact that some stars can't be seen if it is daytime)?
at the equator
Adaptive optics is a technique used to correct telescope images for
atmospheric distortion.
The Chandra X-ray Observatory is in space
because the type of light it observes is not visible from the ground.
A light-year is the
distance light travels in a year.
Light is a means of transporting
energy.
What rays are completely absorbed by the earths atmosphere?
gamma & X-ray
In the electromagnetic spectrum of light, which one has the longest frequency?
gamma rays
Which electromagnetic light has the greatest energy?
gamma rays
Which of the following photons of electromagnetic radiation carry the highest energy?
gamma rays
Galileo's work on the motion of an object was significant because
he conducted experiments with moving objects to verify his rules of motion.
High frequencies of light means _____ energy and ______ wavelengths.
high, longest
visible electromagnetic radiation has a _____ frequency than radio wave electromagnetic radiation.
higher
Blue light has the ______ energy and frequency and the _______ wavelength.
highest, shortest
Angular resolution is
how close two objects can be together before they are viewed as one object.
Apparent retrograde motion in our sky
occurs when a planet appears to move temporarily "backward" in our sky.
A partial solar eclipse occurs when
only part of the Sun's disk is covered by the Moon from the vantage point of an observer on Earth.
The Sun is directly overhead (at the zenith) at noon
only twice a year at locations within the Tropics.
A lunar eclipse is possible
only when a full Moon's orbit intersects Earth's orbital plane around the Sun.
A solar eclipse is possible
only when a new Moon's orbit intersects Earth's orbital plane around the Sun.
Scientific knowledge is reliable because
predictions are tested with experiments and observations.
The Cosmological Principle is the
proposition that natural laws should behave the same everywhere in the Universe.
In the electromagnetic spectrum of light, which one has the longest wavelength?
radio waves
Which of these ranges of electromagnetic radiation has the longest wavelengths?
radio waves
Radio telescopes suffer from poor resolution because
radio waves have such a large wavelength compared to the diameter of the telescope.
From the equator, stars at night will seem to
rise in the east, move overhead, and then set in the west.
A sky observer in the Southern Hemisphere would
see stars moving clockwise around the south celestial pole.
The correct order of steps in the scientific method after making an observation is to
suggest a hypothesis, make a prediction, perform a test.
Copernicus is famous for reviving the ancient Greek idea
that Earth orbits the Sun.
If the velocity of a comet at its closest approach to the Sun is more than its escape velocity, its orbit around the Sun will be
unbound.
The driver of a car who suddenly brakes for a stoplight is
undergoing acceleration because the car is slowing down.
In what part of the electromagnetic spectrum is light with a wavelength of 500 nm?
visible
New moons are completely______from earths surface
visible
What rays completely penetrate the earths atmosphere?
visible & radio
Thin silver moon visible early morning just before sunrise. Which phase of the moon would this be, and in what direction would you look to see the moon?
waning crescent, western horizon
Energy levels are related to ______
wavelength frequency
The energy of a photon depends on its
wavelength.
When the moon appears more than half lit, and is becoming more lit every day, which phase is it in?
waxing gibbous
Which of the following is a type of force? motion, energy, weight, mass, motion
weight
Occam's razor is a guiding principle that states that
when two hypotheses explain a phenomenon well, the one with the fewest assumptions is most likely correct.
On the celestial sphere, the equinoxes are
where the ecliptic crosses the celestial equator.
The precession of the equinoxes is due to the
wobble of Earth as it spins on its axis.
