Astronomy Exam 1

What is the speed of light (c)

300,000 km/s

As a result of the Earth's motion around the sun, the stars will rise

4 minutes earlier than they did the day before

Who is believed to have been the first person to have proposed a heliocentric model eventhough his model was not accepted?

Aristarchus (star in his name)

During a single day the moon rises in the , and sets in the .

East west

During a single day the sun rises in the , and sets in the .

East west

During a single day here in Utah, every star will rise in the East and set in the west (even if we can't see them because it is day time.)

False because Polaris never sets circumpolar constellations

Kepler

He discovered that the best geometric fit for the orbits of the planets according to the observations as elliptical (with the sun at the center)

Newton

He was able to compile all the results into his Law of Gravitation that explained all the motions we see in the sky and on the earth

At 8pm the constellation Gemini is found just over the mountains in the eastern sky. Where will it be about four hours later?

High up in the east

Tycho Brahe

His observatory (though no telescope) was excellent and took many many observations of the locations of the planets in the sky

Cassiopeia is a circumpolar constellation. If in Jan at 8pm it is found low in the North just below the North Celestial Pole, where will it be in July?

It will be high in the north above the celestial pole

Deneb rises in the NE section of the sky. Which part of the sky will it set in?

NW

What is the correct sequence of appearances of Moon phases in the sky over the duration of one lunar month starting with New Moon?

New Moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent, new moon

Give the time that each phase of the moon is at its highest point in the sky

New moon: noon rises at sunrise sets at sunset Waxing crescent: 3 pm rises at 9 am sets at 9 pm First quarter 6 pm rises at noon sets at midnight Waxing gibbous 9 pm rises at 3 pm sets at 3 am Full moon midnight Rises at sunset sets at sunrise waning gibbous 3 am rises at third quarter 6 am rises at midnight sets at noon waning crescent 9 am new moon 12pm

We talked very briefly about the current theory for the time line of the Universe. According to this timeline, when did the Earth form? What are ideas for why the solar system didn't form in the beginning, what about the solar system is necessary that it couldn't have formed earlier on in the age of the universe?

Our solar system is 4.6 billion years old The early universe only consisted of H and He but there are many other elements present in our solar system. Those elements are only formed in dying stars and then recycled back into star systems. That takes time.

Diurnal (daily) motion, the stars rising and setting, the sun rising and setting, the moon rising and setting in one day is caused by...

Rotation of the Earth on it's axis

The name for the time it takes the moon to complete all its phases (time from new moon to new moon)

Synodic (lunar) month

Where would you have to be on the Earth in order to see all the stars rise and set over the course of the year?

The equator

Why does the moon exhibit phases?

The moon is going around the Earth and so depending on where it is in relation to the Sun and the Earth will determine what portion of the Moon that is lit up from Earth's perspective

What occurs because the Earth goes around the sun? (revolution)

The sun is found higher in june and lower in the sky in Dec Constellations are associated with seasons, meaning we see different constellations in the night time sky at different seasons

In science, if new observations disagree with a well established theory then...

The theory must be modified Example of this is Newton's law of gravity. It isn't complete, Einstein's general relativity replaced it for completeness but Newton's can still be used in certain cases.

What would happen if we lived at the North Pole in regards to the stars?

The would not rise or set but instead they would circle around over the days

If I lived somewhere in the middle of the Southern hemisphere (not too near the poles or equator). How would the stars go during the night?

They would rise in the east and set in the west (most of them)

If the people on Earth are seeing the Moon be a Full Moon, what would someone on the Moon be seeing of the Earth?

They would see "New Earth"

If the Earth rotates at a constant rate, why do our summer days have longer periods of sunlight than winter days?

Tild of the Earth

In the course of a single 24 hour period, the Moon rises in the East and sets in the West at some point during that time. True or false?

True

If the moon rotated faster than one rotation per each orbit around the earth what would the difference be?

We would see all sides of the Moon at some point

When does a solar eclipse happen?

When the moon moves between the earth and the sun and it casts a shadow on the Earth

For a person standing on the Earth's south pole (at night) are there stars and constellations that they will not be able to see?

Yes, there are stars they'll never be able to see

What do we call the point where the sun goes from the northern hemisphere to the southern hemisphere of the celestial sphere?

autumnal equinox

What is critical for a scientific theory?

can be tested by observation

The Earth rotates about an axis or line through the middle. If you extend this line into space, it hits the celestial sphere at these points

celestial poles

What information is given by the fact that we only see certain spectral lines in the case of an emission spectra?

chemical composition

Ptolemy

created a mathematical system for calculating the location of the planets through his system had the earth at the center and was very complicated

What word describes the path the sun makes in the sky with respect to the celestial sphere?

ecliptic

The celestial equator and ecliptic intersect at two points called

equinoxes

Just after sunset the star Vega is found near the Zenith. Where will it be at midnight?

further to the west maybe on or just below the horizon

Rank the following in size starting with the largest: star cluster, star, galaxy cluster, and planet

galaxy cluster star cluster star planet

the celestial sphere model we used the first few class periods is which type of model?

geocentric

Copernicus

he reintroduced a sun centered system but the planets orbited the sun in circular orbits

Where will the constellation Gemini be at 8pm four months later?

higher up in the east

This "great circle" (circle drawn on the celestial sphere) cuts the sky into a east and west half. AAll objects reach their highest point in the sky when they cross this line as seen in the above sky

meridian

Which of the Earth's motion accounts for the change of the polar star?

precession

The Earth's orbit around the sun is referred to as

revolution

The Earth spins about its axis with respect to the stars in 23 hours and 56 minutes. What is this time period called?

sidereal day

The time it takes the earth to orbit the sun

sidereal period

Which astronomical objects are found on the Salt Lake Temple?

stars moons big dipper saturn stones

When the sun is at the furthest point north of the celestial equator we call this

summer solstice

Most ancient Greek Models of the universe were geocentric. What was the center of their model?

the Earth

If we could observe the background stars in daylight (like we can in the planetarium) how could the sun appear to move against this background over the course of many months?

the sun would move toward the east with respect to the background stars

Galileo

used the telescope to notice that Venus had phases, Saturn had rings, upiter had moons that followed Kepler's law and there are objects we can't see with the naked eye

As the sun makes its journey through the celestial sphere it passes through constellations referred to as constellations of the

zodiac