Astronomy TEST 1
The eccentricity of the majority of the planetary orbits our Solar System is approximately
0
A circular orbit has an eccentricity of _____________ and a very elliptical orbit has an eccentricity of ________________.
0;1
If there is a full Moon out tonight, approximately how long from now will it be in the third quarter phase?
1 week
(6 x 10^5) x (3 x 10^-2)=
1.8^4
The sidereal period of the moon is closest to
27 days
(1.2 x 10^9) / (4 x 10^-3)=
3 x 10^11
Kepler's third law says that a comet with a period of 160 years will have a semimajor axis
30 AU
What is the approximate number of stars in the Milky Way?
300 billion
If you traveled a velocity of 60 mph for a five-hour trip, how far did you travel?
300 miles
After the Sun, the next nearest star to us is approximately ________ away.
4-light years away
If you start from rest and accelerate at 10 mph/s and end up traveling at 60 mph, how long did it take?
6 seconds
The average distance between Earth and the Sun is 1.5x10^11 m, and light from the Sun takes approximately ___________________ to reach earth.
8 minutes
If Neptune has a semimajor axis of 19 AU, its orbital period is
83 years
A comet orbits the Sun with a semimajor axis of 90 AU. Using Kepler's third, the comet's orbital period is
850 years
Place the following in order from largest to smallest semimajor axis: A. A planet with a period of 84 Earth days. B. A planet with a period of 1 Earth year. C. A planet with a period of 2 Earth years. D. A planet with a period of 0.5 Earth year.
A. A planet with a period of 84 Earth days. (4) B. A planet with a period of 1 Earth year. (2) C. A planet with a period of 2 Earth years. (1) D. A planet with a period of 0.5 Earth year. (3)
The first great event in the history of the universe is called the
Big Bang
No matter where you are on Earth, stars appear to rotate about a point called the:
Celestial pole
The planet Uranus will be observed in retrograde motion when
Earth over takes Uranus in its orbit.
If you were to specify your address in the universe, listing your membership from the smallest to largest physical structures, it would be:
Earth, Solar System, Milky Way, Local Group, Laniakea Supercluster, the universe
Copernicus' model of the Solar System was superior to Ptolemy's because
It had a mathematical basis and computed the spacing of the planets.
Who discovered that planets do not orbit the Sun in circular orbits?
Kepler
If Kepler had lived on Mars, would he have deduced the same empirical laws for the motion of the planets? Explain.
Kepler would have deduced exactly the same three laws of planetary motion. The only difference is that the actual value of an AU would be different. But because a Martian year is different than a year on Earth, the relationship P^2 ∝ A^3 would still be true.
superior planets
Mars, Jupiter, Saturn
inferior planets
Mercury and Venus
Which of these scientists had a mathematical theory with which he was able to explain astronomical discoveries and make predictions, as opposed to analyzing collected data?
Newton
_____________ was the first person to introduce a mathematical heliocentric model of the solar system from which accurate predictions could be made of planets' positions.
Nicolaus Copernicus
Which place has the most circumpolar stars?
North Pole (latitude 90)
Kepler's third law for our Solar System can be expressed mathematically as:
P^2 = a^3
For Earth, P2/A3 = 1.0 (in appropriate units). Suppose a new dwarf planet is discovered that is 14 times farther from the Sun than Earth is. For that planet,
P^2/A^3 = 1.0 (Kepler's third law tells us that P2 = A3for all planets orbiting the Sun)
How did the ancients know the planets were different from the stars?
Planets move differently than stars.
Which scientist made accurate observations of planetary positions?
Tycho
What is the difference between speed and velocity? Between velocity and acceleration?
Velocity is the speed of an object plus its direction. Acceleration is how quickly the velocity of an object is changing. However, an object can travel at constant speed but change direction (i.e., turn), and thus, the velocity is changing, which means the object is accelerating.
If Earth's axis were tilted by 5 degrees instead of it's actual tilt, how would the seasons be different than they currently are?
Winters would be warmer
Imagine a planet moving in a perfectly circular orbit around the Sun. Is this planet experiencing acceleration?
Yes, because it is changing its direction of motion all the time.
A theoretical model is
a detailed description in terms of known physical laws or theories.
The orbit of the planets is an ellipse with the Sun at
a focus
The major component of a physical law that is missing from an empirical is
a theoretical framework
How often do leap years occur?
almost every 4 years
Circumpolar stars are stars that
always above the horizon
One of the central assumptions in astronomy is that the physical laws of nature:
are the same everywhere in the universe
Which of the following is true? a. A scientific theory is an undisputed fact. b. If continual testing of a hypothesis shows it to be valid, it may become an accepted theory. c. A hypothesis must never have one or more testable predictions. d. A scientific theory must not be able to be proven wrong when scientists acquire new data. e. A hypothesis can become a theory without it being tested.
b. If continual testing of a hypothesis shows it to be valid, it may become an accepted theory.
Cars can accelerate forward because
car tires push backwards against the road
If you are above the arctic circle, the majority of the stars in your sky are
circumpolar
An inferior planet is one that
closer to the sun than the earth
According to Kepler's second law, where is the planet located when it moves the fastest?
closest to the star
Kepler's second law says that if a planet is in an elliptical orbit around a star, then the planet moves fastest when it is
closest to the star
A theory is a. Tied to known physical laws b. Able to make testable predictions c. a hypothesis that has withstood many attempts to falsify it. d. all of the above
d. all of the above
A light-hour is a measure of ____________________.
distance
Which on the following are superior planets? a. Mars b. Earth and Venus c. Venus, Mars, Jupiter, and Saturn d. Earth, Jupiter, and Saturn e. Mars, Jupiter, and Saturn
e. Mars, Jupiter, and Saturn
When the Earth catches up to a slower moving outer planet and passes it in its orbit like a faster runner overtakes a slower runner in an outside lane, the planet:
exhibits retrogade motion
A hypothesis is an idea that is
falsifiable
Living in the Northern Hemisphere, you see the Moon with exactly its right half illuminated. This phase is
first quarter
If tonight the Moon is in the waxing gibbous phase, in three days the phase of the Moon will be
full
The scientific method is a process by which scientists
gain confidence in theories by failing to prove them wrong
A ____________ becomes a _____________ when repeated testing of its predictions does not disprove it.
hypothesis; theory
The natural tendency of an object to resist changes in motion is called
inertia
Right ascension is a measure of a star's location on the celestial sphere that is most similar to which measurement of location on Earth?
longitude
The language of patterns, and therefore of science, is
mathematics
At what time does a third quarter Moon rise?
midnight
The point directly below your feet is called the
nadir
In science an idea that cannot be tested is
not a scientific idea
An empirical science is one based on
observed data
If the Polaris has an altitude of 35 degrees, then we know that
our latitude is 35 degrees
Before you can specifically test a hypothesis, you must use the hypothesis to develop a
prediction to test
If nature behaves according to a certain physical law, then that law should result in
repeating patterns
The moon undergoes synchronous rotation, and as a consequence the
rotational period of the moon equals the orbital period of the Moon around the Earth
A scientific theory can be shown to be wrong if
scientists gather new data that contradict its predictions
When the Northern Hemisphere experiences fall, the Southern Hemisphere experiences
spring
The Sun is a
star
On which day of the year does the Sun reach its northernmost point on the celestial sphere?
summer solstice
The day with the smallest number of daylight hours over the course of the year for a person living in the Southern Hemisphere is the
summer solstice (June 21st)
The time it takes for a planet to come back to the same position relative to the sun is called its ___________________ period.
synodic
We experience seasons because:
the Earth's equator is tilted relative to the plane of the solar system
During Summer above the Arctic Circle
the Sun can always be seen.
The Andromeda Galaxy is also part of the Local Group, so it is also part of
the Virgo Supercluster
Because of ___________, we can conclude that gravity works the same way on Earth as it does on Mars.
the cosmological principle
In regard to the phase of the Moon, the term waxing means:
the illuminated area is increasing
Galileo observed what the geocentric astronomers viewed as imperfections. These observations helped Galileo to show that the heliocentric model was the more accurate model. Which was not an observation of Galileos?
the moons of Saturn
If you go out at exactly 9 P.M. each evening over the course of one month, the position of a given star will move westward by tens of degrees. What causes this motion?
the revolution of Earth around the Sun
The ecliptic is the path produced by the apparent motion of ________________ in the sky.
the sun
Planets with high eccentricity may be unlikely candidates for life because
the temperature varies too much
If Earth's axis were tilted by 35 degrees instead of its actual tilt, how would the seasons be different than they are currently
winters would be colder
The point in the sky directly above an observer is called the
zenith
Your meridian is an imaginary circle on the sky that connects the
zenith and the north and south directions