Mastering Astronomy study test 1 part 3 Flashcards
____ is about 30 times as far from the Sun as our own Planet.
Neptune
___ is the planet with the highest average surface temperature.
Venus
The planet with the lowest average density is
Saturn
The planet that orbits closet to the sun is
Mercury
The only rocky planet to have more than one moon is
Mars
___ is the jovian planet that orbits closet to the Sun.
Jupiter
___ has a rotational axis that is tilted so much it lies nearly in the plane of its orbit.
Uranus
Most of the surface of ____ is covered with liquid water
Earth
Planets orbital time
Mercury - 87.97 days, Venus, 224.7 days, earth 365.26 days, Mars, 686.98 days, Jupiter 4,332..82 days, Saturn 10,755.7 days, Uranus 30,687.15 days, Neptune 60,190.3 days Pluto, 90,553 days
How much of the celestial sphere is visible for an observer at 0 degrees south at any one instance?
50%
Approximately how much of the celestial sphere is visible for an observer at 60 degrees north over the course of one 360 rotation of the earth?
60%
Temperatures of planets from hottest to coolest
Sun venus mercury moon earth mars jupiter saturn uranus neptune pluto
Earth has two tidal bulges at all times. Approximately where are these bulges located?
One faces the moon and one faces opposite the moon.
Do tides also affect land?
yes, though land rises and falls by a much smaller amount than the oceans.
Any particular location on Earth experiences.
Two high tides and two low tides each day
One tidal bulge faces toward the Moon because that is where the gravitational attraction between earth and moon is strongest. Which of the following best explains why there is also a second tidal bulge?
the second tidal bulge arises because gravity weakens with distance essentially stretching earth along the earth-moon line
Moon phase and orbital position relative to sun, tides
Low tides are lowest at both full moon and new moon, high tides are highest at both full moon and new moons.
Why does the moon play a greater role in causing tides than the Sun?
Because the gravitational attraction between earth and moon varies more across earth than does the gravitational attraction between earth and sun.
A solar eclipse that occurs when the new moon is too far from earth to completely cover the sun can be either a partial solar eclipse or a
Annular eclipse
Anyone looking from the night side of earth can, in principle see a
total lunar eclipse
During some lunar eclipses the moons appearance changes only slightly because it passes only through the part of earths shadow called the
penumbra
An ____ can occur only when the moon is new and has an angular size larger than the sun in the sky
Total solar eclipse
A partial lunar eclipse begins when the moon first touches earths
Umbra
A point at which the moon crosses earths orbital plane is called an
node
Suppose you are in an elevator, as the elevator starts upward its speed will increase. During this time when the elevator is moving upward with increasing speed, your will be.
greater than your normal weight at rest
Suppose you are in an elevator that is moving upward, as the elevator nears the floor at which you will get off, its speed slows down during this time when the elevator is moving upward with decreasing speed your weight will be
less than your normal weight at rest
For what other motion would your weight also be greater than your normal weight?
The elevator moves downward while slowing in speed
If you are standing on a scale in an elevator, what exactly does the scale measure
the force you exert on the scale
If we have a new moon today, when we will have the next full moon?
In about 2 weeks.
We cannot see a new moon in our sky because _________.
a new moon is quite near the Sun in the sky
The Moon always shows nearly the same face to Earth because ________.
the Moon rotates once in the same amount of time that it takes the Moon to orbit Earth once
A week after full moon, the Moon’s phase is:
third quarter.
The fact that we always see the same face of the Moon tells us that:
the Moon’s rotation period is the same as its orbital period.
In which direction does a quarter Moon rise?
east
If the Moon rises around 3 A.M., its phase must be
waning crescent.
At approximately what time would a first quarter Moon rise?
noon
At approximately what time would a full Moon be on your meridian?
midnight
If the Moon is rising at midnight, the phase of the Moon must be
third quarter.
If the Moon is setting at 6 A.M., the phase of the Moon must be
full.
When someone on Earth observes the Moon in the first-quarter phase, someone on the Moon facing Earth observes Earth in the
third-quarter Earth phase.
If you lived on the Moon, you’d see full Earth when we see new Moon.
True
All of the following statements are true. Which one explains the reason why there is not a solar eclipse at every new Moon?
The orbital plane of the Moon is tilted by about 5∘ to the ecliptic plane.
In addition to the conditions required for any solar eclipse, what must also be true in order for you to observe a total solar eclipse?
The Moon’s umbra must touch the area where you are located.
If part of the full Moon passes through Earth’s umbra, we will see a(n)
partial lunar eclipse.
If the Moon is relatively far from Earth, so that the umbra does not reach Earth, someone directly behind the umbra will see
an annular eclipse.
A solar eclipse occurs only when the Moon is new.
True
About how many stars are visible to the naked eye on a clear, dark night away from city lights?
A couple thousand.
What do astronomers mean by a constellation?
A constellation is a region in the sky as seen from Earth.
What is the ecliptic?
The path the Sun appears to trace around the celestial sphere each year.
What is the celestial sphere?
The celestial sphere is a representation of how the entire sky looks as seen from Earth.
What do we mean when we talk about the Milky Way in our sky?
The patchy band of light that outlines the plane of the Milky Way Galaxy as seen from Earth
Which of the following correctly describes the meridian in your local sky?
A half-circle extending from your horizon due north, through your zenith, to your horizon due south
The point directly over your head is called _________.
the zenith
Stars that are visible in the local sky on any clear night of the year, at any time of the night, are called _________.
circumpolar
We describe a location on Earth’s surface by stating its _________.
latitude and longitude
If you are located in the Northern Hemisphere, which of the following correctly describes a relationship between the sky and your location?
The altitude of the north celestial pole equals your latitude.
Which of the following best describes the meaning of declination and right ascension?
They are coordinates on the celestial sphere, with declination telling us the angular distance of an object from the celestial equator and right ascension telling us how far around the celestial sphere an object is located from the vernal equinox.
The Sun’s declination on June 21st is ______.
+23.5 degrees
Which of the following best describes the Tropic of Cancer?
It is the circle of latitude on Earth for which the Sun appears directly overhead at noon on the summer solstice.
Suppose it is January and the Sun remains above your horizon all day long. Where must you be located?
somewhere between the Antarctic Circle and the South Pole
From a latitude of 60 degrees north during the winter, the Sun will ______.
spend most of each day below the horizon
If you were standing on Earth’s equator, where would you look to see the north celestial pole?
on your horizon due north
Which of the following statements about the celestial sphere is NOT true?
The “celestial sphere” is another name for our universe.
When traveling north from the United States into Canada, you’ll see the North Star (Polaris) getting _________.
higher in the sky
Suppose you use the Southern Cross to determine that the south celestial pole appears 40 degrees above your horizon. Then you must be located at
latitude 40 degrees south
Suppose you are facing north and you see the Big Dipper close to your northern horizon, with Polaris (and the Little Dipper) above it. Where will you see the Big Dipper in six hours?
To the right of Polaris; that is, 90 degrees counterclockwise from its current position
In any particular place on Earth, certain constellations are visible in the evening only at certain times of the year because _________.
our evening view of space depends on where Earth is located in its orbit around the Sun
The Sun’s path, as viewed from the equator, is highest in the sky on _________.
the spring and fall equinoxes
Suppose Earth’s axis tilt was significantly greater than its current 23.5 degrees, but Earth’s rotation period and orbital period were unchanged. Which statement below would not be true?
The length of each season (for example, the number of days from the summer solstice to the fall equinox) would be significantly longer than it is now.
How does Earth’s varying distance from the Sun affect our seasons?
It doesn’t — Earth’s orbital distance plays no significant role in the seasons.
Which of the following statements is not true about the sky at Earth’s equator?
The Sun will pass directly overhead around noon each day.
Suppose Earth’s axis had a greater tilt (more than 23.5 degrees). Which of the following statements would not be true?
The celestial sphere would be covered by a different set of constellations than it is with the current axis tilt.
