Astronomy
#10
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26
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How many months of the year is the sun above the celestial equator?
6
How did Eratosthenes estimate the size of the earth in 240 bc?
By comparing whether sun light could reach water down in water wells in two cities at different latitudes and using simple trigonometry.
The controversial book De Revolutionibus of this famous person, published in 1543 (the year of his death), revived the heloicentric model in which the earth and other planets orbited the sun- an idea that was not popular! This book was later banned.
Copernicus
ptolemy was important in the history of astronomy becasue he?
Developed a geocentric model of the solar system that made sufficiently accurate predictions to remain in use for many centuries even though it was horribly contrived
By the "observable universe" we mean that we can observe the physical edge of our universe which is where the universe ends; consequently we know the size of our universe
False
He discovered that jupiter has moons becasue he was first to use a telescope
Galileo
Aristotles idea of the cosmos was
Geocentric with the celestail bodies made of a light substance called quintessance floating above a heavy earth
When Venus has the greatest angular seperation from the sun, it is at its highest in the sky appearing as a morning "star" or evening star. During these times we say Venus is at
Greatest Elongation
How does copernicus account for the retrograde motion of Mars in his ideas of the cosmos?
He says the retrograde motion is an illusion orapparent motion due to earth passing or lapping mars in its orbit, and mars being closer than the background "fixed" stars
How did the Ptolemaic model exxplain the apperant retrograde motion of the planet?
It held that the planets moved along small circles called epicycles that moved on larger circles all deferents around the earth. Thsi combined motion resulted in retrograde motion.
He discovered that the orbits of planets are ellipses which was contained in the first of his 3 laws.
Kepler
The names of the seven days of the week are based on the
Sun,moon, and five planets that are easily visible by the naked eye
If Neil Armstrong stayed on teh moon for several weeks, he would notice which of the following?
The earth would exhibit phases , but would not rise or set. The sun qould rise and set
What is the apparent path of the sun along the celestial sphere, ( or equivelantly the plane determined by the earths orbit) called?
The ecliptic
Which of the following is not a consequence of Keplers second law
The farther the planet orbits from the sun, the greater the speed of orbit, making the farthest planets orbit the fastest
what conditions are required for a solar eclipse
The phase of the moon must be new, and the nodes of the moons orbit must be nearly alligned with the earth and the sun
All of the following are true. Which of the following is a consequence of the precision of the earths spin axis?
The sidereal period for earth is 365.26 days.
Why do we have seasons on earth
The spin axis of the earth tilted 23.5 degrees with respect to a line normal to the plane of orbit. This causes the northern and southern hemispheres to alternately recieve more and less direct sunlight.
on which day is the spin axis of the earth tipped directly toward the sun
The summer solstice
On the day for the vernal equinox (spring equinox) which of the following is Not true?
The sun rises farthest to the north, in the northeast that day
on the day of the winter solstice we notice that
The sun rises north of due east, in the north east
Which of the following is not true about the galaxies in our local group
There are about 100 billion galaxies in our local group- most of them are dwarf galaxies
How are heavier elements (that is elements greater in atomic number than lithium) produced?
They are produced by stars in supernovae
If you watch the position of mars against the background or "fixed" stars from the month to month you notice that mars appears to move eastward but then stops and moves westward, only to stop again and resume its eastward motion making a loop in the sky. whats going on?
This motion is best described by Mars moving along an epicycles which in turn is moving along a deferent
Does the moon rotate on its axis
Yes, the moon spins once on its axis every 24 hours just like earth does
On the scale of the cosmic calender, in which the history of the universe is compressed to 1 year, how long has human civilization (i.e. since ancient egypt) existed?
a few seconds
If the moon moves entirely into the umbra of the earth we have
a total lunar eclipse
How long does it take light to travel from the sun to earth
about 8 minutes
Before scientists accept a scientific theory there must be
all of the above
What si stellar parallex?
an apparent shift in the position of a nearby star against a background of far away "fixed" stars due to a change in the position of the observer
If a planet orbits a star in an eclipse with a star at approximently one focus point, when the planet is farthest away from the star, we say the planet is at
aphelian
which of the following is in order of increasing length
diameter of the sun, astronomical unit, light year, parsec
It is sunset and the moon is on your meridian. WHat it the phase of the moon?
first quarter
At approximently what time would a full moon be on your meridian
midnight
If mars is on your meridian and it is midnight, we say that Mars is at
opposition
What is the saros cycle?
the 18-year 11.3 day cycle over which the pattern of the eclipse repeats
In class we have been following a current mission which is
the launch of a space probe called grail on route to the moon
Orion is visible on winter evenings but not summer evenings because of?
the location of the earth in its orbit
A lunar eclipse and a solar eclipse does not occur every month because
the orbit of the moon is tilted with respect to the plane of the ecliptic which causes the shadows involved to miss falling on the moon or earth for an eclipse
Polar bears that live at latitudes equal to or above the artic circle notice
the sun does not set on the day of the summer solstice
On the day of the autumnal equinox and on the day of the vernal equinox the length of the daylight hours and nightime hours are equal for everyone on earth (12 hours each of day and night).
true
On the vernal equinox the spin axis of the earth and a line between the earth and the sun are perpindicular.
true
One of the greatest debates in the intellectual history of mankind was whether the geocentric or heliocentric cosmos was correct. The first recorded model of the heloicentric cosmos was proposed by Aristarchus before the birth of christ
true
Which of the following has your "address" in order of increasing size beginning with you>
you,earth,solar system, milky way, local group, local supercluster.
If direction that is directly over head is your
zenith
