Astronomy Midterm
The Galileo space craft measured that the moon Ganymede had a magnetic field, indicating that it's interior was at least partly melted and warm. What do scientist think is the most likely reason for this
Ganymede is heated by tidal forces from Jupiter
The "prime meridian" (where longitude equals zero) passes through:
Greenwich, England
When astronomer say that Ganymede is a differentiated body, they mean that it
Has a heavier core, surrounding by lighter, icy mantle and crust
By far the most abundant element in the giant (jovian) planets is:
Hydrogen
If you were to take a large sample of four giant planets, the most common element you would find in them is
Hydrogen
Any rock in the earths crust that has cooled from an original molten state is called
Igneous
What features are abundant on Callisto and Ganymede and almost absent on Europa and lo
Impact craters
The jovian planet that has the longest year (period of revolution) is:
Neptune
In what way is the moon similar to the earth
None of the above
Callisto, the fourth Moon of Jupiter is, takes 17 days to orbit Jupiter. If I stand on the surface of Kalisto and see Jupiter high in the sky over my head, and then we eat. Five Earth Day's in the same spot, where will I see Jupiter
Overhead, where it was before
The material that would eventually make all the major bodies in our solar system first gather together a smaller pieces which astronomers call
Planestesimals
The planet in our solar system whose orbit actually brings it inside the orbit of another planet is
Pluto
Which planet has the biggest moon relative to it own size? Not the biggest moon in terms of kilometers, but the biggest as a percentage of the size of the planet it orbits
Pluto
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 moved 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
What do you astronomers think is the origin of the many irregular moons around the outer planets (irregular meaning they are orbiting backwards and/or have eccentric orbits)
These moons were likely formed elsewhere and captured by the giant planets
What is one important way in which both the moon and mercury are different from earth
They do not have an atmosphere
The 17th century astronomer who kept a roughly 20 year continuous record of the positions of the sun, moon, and planets was
Tycho Brahe
What specific event really made it possible for the three laws of planetary motion to be discovered
Tycho Brahe died and his assistant was able to get full access to his data
The planet that most resembles the earth and size and internal composition
Venus
What planet can come closest to the earth and its orbit and look brightest in our skies
Venus
What is the most important reason that astronomers have learned more about our planetary system in the last 30 to 40 years then all of history before then
We have been able to send spacecraft to gather information about planets and moons up close
Which of the following is not a way that the moon titan probably resembles the earth
at its surface the temperature and pressure are just right for water to exist in all three phases (gas, liquid, and ice)
If you could see the new moon, at what time of day (roughly) would it rise?
at sunrise
Which of the following statements about our moon is false
on Earth, we can see all its sides in the course of a month as it goes around us
What would you have to change about the Earth to stop our planet from having significantly different seasons
the tilt of its axis
In studying the surfaces of solid bodies in the solar system, astronomers have learned that the number of craters per unit area
is roughly proportional to the age of the surface we are examining
The dwarf planet Pluto was discovered in 1930. Since that time, which Jovian planet has completed a full revolution around the sun
more than one of the above
Which of the following is not one of the key reasons that so many spacecraft from earth have visited Venus and mars
their atmospheres are very similar to the Earth in terms of their chemical make-up
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
Which of the Jovian planets does not have any satellites
you can't fool me, all the jovian planets are accompanied by satellites
Which planet in the solar system has not been examined by spacecraft instruments that have either flown by or orbited them
you can't fool me, spacecraft have visited all the planets in our solar system
The time it takes for the Sun to return to the same place in our sky after the earth has rotated once it's called
A solar day
According to the fossil record, how old is the oldest evidence of lifeforms on the surface of the earth?
About 3.5 billion years
One way in which the ozone layer is used for lifeforms on the earth surface is that it
Absorbs ultraviolet light, preventing much of it from reaching the surface
Why do many people consider Isaac newton one of the greatest scientist who ever lived
All of the above
Which ancient Greek thinker suggested (long before Copernicus) that the Earth is moving around the Sun?
Aristarchus
The primary clouds in the atmosphere of Jupiter and Saturn are composed of
Frozen ammonia Crystal
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 is moving away from the Earth not falling freely around it.)
1 lb
A star is 230 light years away. The light we see tonight from that star left it
230 years ago
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 scientist are very doubtful that I can predict anything meaningful about our lives
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
The 88 sectors into which astronomers today divide the celestial sphere (the whole sky) are called
Constellations
The Renaissance astronomer who wrote the pioneering book that suggested the Earth probably orbits the Sun (instead of the other way around) was:
Copernicus
The satellite whose surface is characterized by a smooth icy crust with a complex network of cracks is:
Europa
What is the source of the fine, powdery dust found on the moon surface
It is the a result of many impacts, breaking surface rocks apart over billions of years
The big problem with the Galileo spacecraft is that
It's main antenna is stuck in the closed position
The Earth is closest to the sun in which month of the year
January
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
A planet in our solar system who's composition resembles that of our Sun is
Jupiter
Which of the Jovian planets has the shortest period of rotation (The shortest day) ?
Jupiter
The first human being to step out onto the surface of another world was
Neil Armstrong
The spacecraft that sent back the most detailed radar images of Venus that showed us features as small as a football field is
Magellan
The largest part of the earth is it
Mantle
The large roughly circular, dark, younger regions on the moon are called what?
Maria
An important way that scientist have been able to study the interior of the earth is by
Measuring how seismic waves are transmitted through the Earth
The planet closest to the sun in our solar system is
Mercury
The great astronomer of ancient times to summarize and improve a system of circles upon circles to explain the complicate emotions of the planets (and publish the system in a book now called The Almagest) is
Ptolemy
I want to examine the surface of a planet which is completely covered by thick layer of clouds all the time. What wavelength of electromagnetic radiation would be smartest to use
Radio waves (like radar)
Scientist have been concerned about a set of industrial chemicals called CFC's (chlorofluorocarbons) because they
Rise into the atmosphere and destroy ozone
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 around
The Sun is seen blocking different constellations in the course of a year
What was a surprise to astronomers when they carefully examine Neptune with the Hubble space telescope in 1994
The gray dark spot had disappeared
Why does Mars have an overall reddish color when we see it surface from a far
The material of Mars surface contains a lot of iron oxide, the same chemistry that makes resting metals look reddish
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, circle to a point near the earth
The same process that explains why astronomer see less helium in the upper atmosphere of Saturn when they take spectra also explains
The reason Saturn is warmer than we expect
The star that provides energy for life on Earth is
The sun
The point in the sky directly above your head at any given time is called
Zenith
The location of the Earth in the Milky Way Galaxy is
a little less than 30,000 LY from the center
Which of the following is a way we believe that the early atmosphere of the earth differed from the atmosphere we have today?
all of the above
Which of the following is not a correct statement about the ways the Jovian planets differ from the terrestrial planets
all the jovians have satellites around them and none of the terrestrials do
Within a constellation, a smaller, recognizable pattern of stars is often called:
an asterism
We now know that the orbit of a stable planet around a star like the Sun is always in the shape of:
an ellipse
We believe the Maria on the earths moon are
ancient impact craters in which lava beds welled up from inside the Moon
The mountains on the moon
are the result of giant impacts during the Moon's long history of being hit
Why is there a 4-minute difference between the solar day and the sidereal day?
because the Earth is going around the Sun in the course of a year
How did Eratosthenes measure the size of the Earth?
by measuring the height of the Sun in the sky on the same day in two cities at different latitudes
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
The same gas makes up most of the atmosphere of Mars and Venus. This gas is
carbon dioxide
Which part of the earth has the greatest density
core
What is one way that astronomers have actually gotten an idea of the age of surfaces of terrestrial planets other than the earth
counting craters
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
Of the people who landed on the Moon, how many were trained scientists?
exactly one
When it comes to our place in the solar system today, which model do we except
heliocentric
The number of degrees of arc that your location is north or south on the earths equator is called your
latitude
The upper clouds in the atmosphere of Neptune are composed of
methane
The rate at which a collection of the same radioactive atoms will decay depends on
only on internal processes within the atoms; nothing external matter should
The slow tipping of the Earth's axis in a circle with a period of about 26,000 years is called:
precession
Rocks that have not been chemically modified by being significantly heated are called
primitive
The lunar highlands are made mostly of rocks that
rose to the top as the Moon cooled from a molten state early in its history
According to the theory of plate tectonics
slow motions within the mantle of the Earth move large sections of the crust around
The majority of the moons orbiting the outer (Jovian) planets are
small moons orbiting in a retrograde direction (opposite to the direction their planet turns and orbits)
Our best evidence and theoretical calculations indicate that the solar system began with a giant spinning system of gas and dust that scientists call:
solar nebula
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
A light year is
the distance that light travels in one year
The celestial sphere turns once around each day because
the planet on which we live on is rotating