Astronomy Exam 1
The latitude of the Earth's equator is
0 degrees
An astronomy textbook, when printed out, weighs four pounds on the surface of the Earth. After finishing your course, you are so tired of the book, you arrange for NASA to shoot it into space. When it is twice as far from the center of the Earth than when you were reading it, what would it weigh? (Note, assume that the book has been moving away from the Earth, not falling freely around it.)
1 lb
From horizon to opposite horizon, the sky takes up how much angular distance?
180 degrees
A star is 230 light years away. The light we see tonight from that star left it _____
230 years ago
Light travels 3 x 108 meters every second (after rounding). That number in words is ______
300,000,000 meters
The location of the Earth in the Milky Way Galaxy is_____
A little less than 30,000 LY from the center
Credit for the discovery of Neptune is shared by two astronomers. They are:
Adams and Leverrier
As seen from the continental United States, the Big and Little Dipper
Are in the north circumpolar zone throughout the year
Which ancient Greek thinker suggested (long before Copernicus) that the Earth is moving around the Sun
Aristarchus
The "prime meridian" (where longitude equals zero) passes through:
Greenwich, England
Why do many people consider Isaac Newton one of the greatest scientists who ever lived?
He formed the laws that govern all motion in the universe He combined the work of Galileo, brache, and Kepler into one framework He figured out the mathematical form of a law of universal gravity
The scientist who formulated the three laws of planetary motion by analyzing the data on the precise location of planets in the sky was:
Johannes Kepler
When NASA and a group of astronomers sent up a spacecraft designed to find planets orbiting other stars, they named it after Kepler. Why was this an appropriate name?
Kepler figured out the rules of planetary motion, which planets in our solar system and planets elsewhere must obey
A very rich, very shady international banker (with residences all over the globe, including Bayonne, New Jersey) mysteriously disappears. Someone later mails a wide-angle photo of his body to a London newspaper, taken on June 22, showing the Sun exactly overhead at noon. What can the police deduce from this photograph about where on Earth the body is located?
On the tropic of cancer (23 degree north)
Small changes in the orbits of planets caused by the gravitational pull of the other planets in the solar system are called:
Pertubations
The star that is currently closest to the North Celestial Pole is:
Polaris
The slow tipping of the Earth's axis in a circle with a period of about 26,000 years is called:
Precession
The great astronomer of ancient times who summarized and improved a system of circles upon circles to explain the complicated motions of the planets (and published the system in a book now called The Almagest) is:
Ptomely
Someone who observes the sky every clear night in Boston for many years will NEVER get to see:
South Circumpolar zone
In what location on Earth could an eager math student NOT use her solar-powered calculator at any time at all during the course of a day in June?
South Pole
The Astronomical Unit (AU) as defined by astronomers is______
The average distance between the earth and the sun
A light year is ______
The distance light travels in a year
In Ptolemy's system the planets orbit the Earth and not the Sun. How did the system explain the retrograde motion of planets like Jupiter?
The planets moved on a small circle whose center, in turn, circled a point near the earth
The star that provides energy for life on Earth is ______
The sun
The 17th century astronomer who kept a roughly 20 year continuous record of the positions of the Sun, Moon, and planets was:
Tycho brache
Newton showed that to change the direction in which an object is moving, one needs to apply:
a force
A large body in space that consistently makes its own light (instead of merely reflecting another body's light) is called_____
a star
During the period we have daylight savings time, we
add one hour to local standard time
Within a constellation, a smaller, recognizable pattern of stars is often called:
an asterism
The smallest piece of an element (like gold or lead) that still has all the properties of that element is called _____
an atom
We now know that the orbit of a stable planet around a star like the Sun is always in the shape of:
an elipse
When a comet like Comet Hale-Bopp comes closest to the Sun in its orbit, we say that it is at:
apogee
Based on the scientific and statistical tests of astrological predictions, which of the following statements is the most reasonable?
astrology has not passed any clear scientific or statistical test and, as a result, most scientists are very doubtful that it can predict anything meaningful about our lives
Where on Earth do stars always circle the zenith (and never rise and set)?
at the North Pole
Why is there a 4-minute difference between the solar day and the sidereal day?
because the earth is going around the sun in a course of a year
To come up with the precise mathematical form of his law of gravity, Newton first had to invent the mathematical techniques that we now call:
calculus
he minimum speed required to launch an object so that it remains the same distance above the ground and just falls around the Earth is called:
circular satellite velocity
The 88 sectors into which astronomers today divide the celestial sphere (the whole sky) are called:
constellations
Which of the following was NOT done by Hipparchus, the great ancient astronomer? created the system of star magnitudes that we still use today discovered that the Earth has a motion called precession compiled a pioneering catalog of the positions of hundreds of stars explained retrograde motion
explained retrograde motion
Which of the following was NOT done by Galileo Galilei?
explaining retrograde motion with a heliocentric hypothesis
According to Kepler's 2nd Law, comets (which have eccentric orbits) should spend a lot more of their time:
far from the sun
After a long night of cramming for a test, your college room-mate hits his head forcefully against the wall of your room in despair. According to Newton's 3rd Law, as he exerts a force against the wall, there must be an equal and opposite force. How does that opposite force show itself in this case?
he wall exerts a force on your room-mate's head and he has a headache
When it comes to our place in the solar system today, which model do we accept?
heliocentric
Typically, astronomers express the right ascension of a star on the sky in what units?
hours, minutes, seconds
You are on a camping trip, far away from city lights. You look up into the dark night sky, and see lots of stars, some brighter, some dimmer. All the stars you see with your unaided eye are______
in the Milky Way galaxy
The idea that objects (in the absence of an outside force) tend to continue doing what they are already doing is called the law of
inertia
The Julian calendar made the significant advance of:
introducing the leap year, so that every fourth year had an extra day
Which of the following statements about the force of gravity is FALSE?
its strength is inversely proportional to the mass: the more mass, the less gravity
The Earth is closest to the Sun in which month of the year?
january
In Australia (in the Southern Hemisphere), when are the days the shortest and the nights the longest?
late June
The number of degrees of arc that your location is north or south of the Earth's equator is called your:
latitude
In locating objects on the celestial sphere, we call the number of degrees east or west that something is from Greenwich, England its:
longitude
The planet Neptune was discovered by means of:
mathematical calculations of how it was perturbing the motion of a neighbor planet
According to the geocentric view, everything in the heavens had to go around the Earth, which was the center of the universe. What objects did Galileo discover with his telescope that clearly didn't go around the Earth?
moons around the planet Jupiter
When a planet, in its orbit, is closer to the Sun, it:
moves faster than average
The planet in our solar system whose orbit actually brings it inside the orbit of another planet is:
neptune
When a planet temporarily moves westward in the sky over the course of several weeks or months (instead of eastward, as it typically does), we call it:
retrograde motion
If you want to locate someone precisely on the surface of the Earth, you specify her exact latitude and longitude. If you want to locate a star precisely on the sky, you need to specify its exact:
right ascension and declination
The time it takes for the Sun to return to the same place in our sky after the Earth has rotated once is called:
solar day
The first artificial satellite the human race lofted into orbit was called:
sputnik
A "New Age" bride and groom, who are enchanted by the Sun, want to get married on the day when it gets to be highest in the sky. If they live in the United States, around what day of the year will the wedding take place?
summer solstice
At which of the following locations on Earth is the direction we call East not clearly defined?
the North Pole
Which of the following is NOT an argument for showing that the Earth must be round: the height of the North Star changes as we travel to different latitudes the Sun is seen blocking different constellations in the course of a year photographs of the Earth from space always show a round body during an eclipse of the Moon, the shadow of the Earth is always seen to be round The scientist who first devised experimental tests to demonstrate the validity of the heliocentric model of the solar system was when ships travel a large distance away, we see their hulls disappear first and their masts disappear last
the Sun is seen blocking different constellations in the course of a year
Newton's reformulation of Kepler's third law allows us to measure the masses of bodies in orbit around each other, if we can measure:
the distance and periods of revolution
Why was the problem of devising a workable yearly calendar so difficult on Earth?
the earth's rotation period does not divide evenly into the earth's period of revolution
If the Earth goes around the Sun, why is the ecliptic not lined up with the celestial equator?
the earths axis is tilted about 23 degrees from the vertical
In an ellipse, the ratio of the distance between the foci and the length of the major axis is called:
the eccentricity
The Sun's apparent path around the celestial sphere is called
the ecliptic
Every celestial object appears to go around the Earth once a day. In addition to this motion, which celestial object has the fastest apparent motion in the sky?
the moon
The natural object (not one that humans built) in space that's closest to Earth is
the moon
The Earth's escape speed (the speed you need to get away forever) is about 25,000 miles per hour. Escape speed depends on the gravity of the object trying to hold the spacecraft from escaping. Based on your understanding of gravity, how will the escape speed from the Moon compare to the escape speed from Earth
the moon's escape speed will be smaller than the earths
For scientists, an element (like gold) is defined by______
the number of protons in its nucleus
The celestial sphere turns once around each day because____
the planet on which we are living is rotating
The seven days of the week are named after:
the seven "wandering objects in the sky that were visible to the ancients
Why do astronauts (and cans of soft drink) float around in the Shuttle instead of falling?
the shuttle is falling around the earth (and everything inside is free falling)
Which of the following is NOT a result of the Earth's precession? the Earth wobbles (like a spinning top) with a period of 26,000 years the stars twinkle when seen from the surface of planet Earth the signs of the zodiac most astrologers use are no longer in accord with the constellations in which the Sun is currently found over the course of the year Polaris will no longer be the North Star in several thousand years where the Earth's axis points in the sky changes over the centuries and millennia
the stars twinkle when seen from the surface of planet Earth
The terms "a.m." and "p.m." (as in see you at the movies at 8:30 p.m.) derive from what astronomical idea?
the sun passes through the meridian in roughly one day
Which of the following is an important part of the reason it is hotter in summer in North America than in winter?
the sun rays hit more directly in the summer
What would you have to change about the Earth to stop our planet from having significantly different seasons
the tilt of its axis
How did the world's countries solve the problem that mean solar time varies continuously as a traveler's longitude changes?
the world is divided into 24 time zones, with all communities within a time zone keeping the mean standard time
Let's say we find a star that is located on the points or circles in the sky listed in the answer choices below. Then, on the same night, we move to a location on Earth that is some significant distance from our first location. There will now be a different star at or on_____
the zenith
The strip of the sky through which the Sun, the Moon, and the bright planets appear to move in the course of a year is called:
the zodiac
Why do satellites launched into low-Earth orbits not remain there indefinitely?
they lose speed due to friction with the upper layers of the earth's atmosphere
All molecules (like molecules of water or carbon dioxide) are made up of____
two or more atoms
What specific event really made it possible for the three laws of planetary motion to be discovered?
tycho brace died and his assistant was able to get full access to his data
Which of the following statements about the International Date Line is correct?
when crossing west to east, you must decrease the date by one day
Astronomers discover a new comet that orbits the Sun, but has its aphelion (the furthest point in its orbit) beyond Neptune. Astronomers studying this comet have the right to expect that it:
will follow Newton's laws of motion
A single star in the process of forming starts by spinning slowly (while it is quite large and relatively cool.) As the star collapses under the pull of its own gravity, its size decreases. As a result, its rate of spinning:
will increase
The point in the sky directly above your head at any given time is called the
zenith
The scientist who first devised experimental tests to demonstrate the validity of the heliocentric model of the solar system was
Galileo
In what fundamental way did the work of Galileo differ from his predecessors who had thought about the sky?
Galileo relied on instruments and experiments to reveal to him what Nature was doing, rather than on pure logic alone.
What problem has precession caused for many of the schools of astrology?
Because of precession, the constellations are no longer lined up with the astrological signs that are named after them; since astrology was set up, the two have slipped one sign apart
How did Eratosthenes measure the size of the Earth?
By measuring the height of the sun in the sky on the same day at two different latitudes
The Renaissance astronomer who wrote the pioneering book that suggested the Earth probably orbits the Sun (instead of the other way around) was:
Copernicus
In Copernicus' day, people were worried about the idea that the celestial sphere seemed to turn around us once a day because the Earth rotates. They argued that if the Earth were to rotate so fast, it should fly apart. According to our textbook, what was one response Copernicus had to this worry?
Copernicus argued that the idea that the much larger celestial sphere is turning once a day (and the Earth is not) meant that the celestial sphere would be torn apart even more
The way scientists know that a hypothesis in astronomy is a reasonable description of nature is to
Do experiments and observations about the predictions of the hypothesis
Even with the best and largest telescopes, we can't see all the stars in the Milky Way Galaxy, even though these same telescopes can show us other galaxies. Why is that?
Dust in the space between stars builds up over large distances and blocks the light of stars behind the dustier parts of the Milky Way galaxy
According to Kepler's third law, there is a relationship between the time a planet takes to revolve around the Sun and its
distance from the sun
To leave the gravitational pull of the Earth, and explore other planets, satellites must have at least:
escape velocity
By the term universe, astronomers mean
everything we can observe
