Astronomy 1,2 – Flashcards

Unlock all answers in this set

Unlock answers
question
Why did early civilizations observe constellations?
answer
for practical reasons, such as navigation and helping to determine seasons
question
What conditions are necessary for a total solar eclipse?
answer
new moon on ecliptic near perigee
question
The parallax shift of a star would be greater if viewed from Mars than from Earth.
answer
true
question
The orbits of most of the planets in our solar system have eccentricities close to zero.
answer
true
question
If Earth rotated twice as fast as it currently does, but its motion around the Sun stayed the same, then
answer
the night would be half as long.
question
What conditions must exist for a solar eclipse to occur?
answer
The phase of the Moon must be new and the Moon must be passing through Earth's orbital plane.
question
What conditions must exist for a lunar eclipse to occur?
answer
The phase of the Moon must be full and the Moon must be passing through Earth's orbital plane.
question
If you could change the layout of the solar system, which of the following would cause a lunar eclipse to occur at least once every month in this hypothetical situation?
answer
Change the Moon's orbital plane so it is in the same plane as Earth's orbit around the Sun.
question
From Earth, the Sun and Moon have about the same angular diameter.
answer
true
question
Combining Newton's and Kepler's laws, we can weigh the Sun, provided we know:
answer
the size of the A.U. and exact length of the year.
question
Newton's modification of Kepler's Laws allows us to find the ________ of the planets, if we can observe satellites in orbit about them.
answer
masses
question
If the distance between two asteroids is doubled, the gravitational force they exert on each other will:
answer
be one fourth as great.
question
Kepler based his theories on the precise planetary observations of Tycho Brahe.
answer
true
question
Where on Earth would you be if Polaris was at your zenith?
answer
north pole
question
On which of these assumptions do Ptolemy and Copernicus agree?
answer
All orbits must be perfect circles.
question
Galileo found the rotation period of the Sun was approximately:
answer
a month.
question
Like the Sun and the Moon, the stars appear to move from west to east from one day to the next
answer
true
question
A planet whose distance from the Sun is 3 A.U. would have an orbital period of how many Earth-years?
answer
square root of 27
question
Galileo's observations of sunspots proved the Sun was rotating, like the Earth.
answer
true
question
What conditions are necessary for an annular solar eclipse?
answer
new moon on ecliptic at apogee
question
Only at the equator are all the stars visible over the course of the year.
answer
true
question
Today we rely largely on what technique to precisely measure distances in the solar system?
answer
radar echo timings
question
About how many stars are visible on a clear, dark night with the naked eye alone?
answer
a few thousand
question
Compared to orbital velocity, escape velocity is about:
answer
40% more.
question
Halley's comet has a perihelion distance of 0.6 AU AU and an orbital period of 76 years. What is the aphelion distance of Halley's comet from the Sun?
answer
35 AU
question
The places where the Sun crosses the equator are called the:
answer
equinoxes.
question
From a location in the United States of America, a star is observed to be rising due East. Where will this star be located 6 hours later?
answer
high in the southern sky
question
An accurate sketch of Jupiter's orbit around the Sun would show
answer
a nearly perfect circle.
question
The place the Sun stops its northward motion along the ecliptic is the:
answer
summer solstice.
question
The place in a planet's orbit that is closest to the Sun is called:
answer
perihelion.
question
Escape velocity is the speed required to:
answer
overcome the gravitational pull of an object.
question
If you are in the Moon's umbral shadow, then you will witness:
answer
a total solar eclipse.
question
The greatest contribution of the Greeks to modern thought was:
answer
the development of scientific inquiry and model building.
question
When the Sun rises, it is located in the constellation Gemini. When the Sun sets later that same day, it will be:
answer
in the constellation Gemini.
question
While watching a star, you see it moves 15 degrees across the sky. How long have you been watching it?
answer
15 minutes
question
Kepler's second law implies what about planetary motion?
answer
A planet moves faster when it is closer to the Sun.
question
A star with a large parallax:
answer
is at a short distance from Earth.
question
You note that a particular star is directly overhead. It will be directly overhead again in:
answer
23 hours 56 minutes.
question
The angular size of an object depends on which two quantities?
answer
the object's actual size and its distance from us
question
The Ptolemaic model probably persisted for all these reasons EXCEPT:
answer
it accounted well for Galileo's observations of the phase cycle of Venus.
question
The last quarter phase of the Moon:
answer
crosses the meridian at sunrise.
question
Which of the choices below correctly lists things in order from largest to smallest?
answer
Universe, Local Group, Milky Way, Solar System
Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New