ASTROLOGY EXAM REVIEW #1

At what time will the moon be highest in the sky?

dusk

The temperature of the protoplanetary disk allowed

rocks and metals to freeze both in the inner region and outer region, and hydrogen compounds to freeze only in the outer region

For people in Australia, the first day of spring is approximately ____________.

sep 21

Compared to a cold object, a hotter object of the same size emits most of its light at __________ wavelengths and emits _____ light overall.

shorter, more

When you listen to the radio, you are hearing

sound waves

The shadow cast by a simple stick or obelisk allowed ancient people to

tell the time of day

An original observation of Galileo's that helped to overturn the ancient Earth-centered model was

the phases of Venus

A bowling ball and a small marble will fall downward to the surface of the Moon at the same rate because ____________.

the ratio of the force of gravity exerted on an object to the object's mass is the same.

A kilogram is a measure of an object's ____________.

mass

The Moon takes roughly 28 days to complete one orbit around Earth. If the orbital radius of the Moon were twice its actual value, its orbital period would be

more than 56 days. Submit

If a hot gas cloud is moving across the sky (neither towards or away from us), the emission lines would be

neither blueshifted nor redshifted.

In Ptolemy's Earth-centered model, when would Venus appear directly behind the Sun as viewed from Earth?

never

A total solar eclipse can only happen during what lunar phase?

new moon A solar eclipse occurs when the Moon's shadow falls on Earth, which can only happen when the Moon is between the Earth and Sun, which means during the new Moon

When the Sun dies it will become a white dwarf, which will be roughly the same size as the Earth. Assuming the Sun doesn't lose any mass as it becomes a white dwarf, the force of gravity exerted on Earth due to the Sun will ____________.

not change as the Sun turns into a white dwarf

full moon

occurs 14 days after new moon rises at about the time the sun sets visible due south at midnight

Suppose you live at a mid-latitude in the Southern Hemisphere (such as in Australia, New Zealand, Chile, or South Africa). When will you have 12 hours of daylight and 12 hours of darkness?

on both the March and September equinoxes

The existence of a core-mantle-crust interior structure tells us that a world __________.

once had a molten interior

The "giant impact hypothesis" refers to the idea that ___________.

our Moon formed when a Mars-size object collided with the young Earth.

The planets in our solar system are thought to have come from

the same cloud of gas and dust in which the Sun formed.

If the solar nebula initially had no angular momentum,

there would not be any planets orbiting the Sun.

. We determine Mars's surface temperature from the peak wavelength of the ______ it emits.

thermal radiation

Do you think Northern Hemisphere summers are warmer or colder than Southern Hemisphere summers on Mars

they are colder

Do you think Northern Hemisphere winters are warmer or colder than Southern Hemisphere winters on Mars?

they are warmer

If the emission lines in the spectrum of one object are more strongly blueshifted than those from a second object, then the first object is moving

toward us faster than the second object.

On Dec. 21, the Sun is directly above the ____________.

tropic of Capricorn (latitude = 23.5 degrees S)

By only measuring an object's Doppler shift, astronomers tend to

underestimate the object's total speed.

The color of Mars in our sky is determined by the ______ of Mars's spectrum.

visible portion

If the Earth were tilted 90 degrees (rather than 23.5 degrees), summer in the Arctic would be ____________ summer in Colorado.

warmer than

Pluto

was studied up close in 2015 by the New Horizons spacecraft.

An astronomer looks at the Andromeda galaxy (the other large galaxy in the Local Group) through her telescope. How long ago did that light leave Andromeda?

2.5 million years

first quarter moon

A first quarter moon rises at about noon, reaches its highest point in the sky at about sunset, and sets around midnight.

a full moon

A full moon rises at about sunset, reaches its highest point in the sky at midnight, and sets around sunrise.

a new moon

A new moon rises at about sunrise, reaches its highest point in the sky at about noon, and sets around sunset.

What is the basic reason that we have seasons on Earth?

Earth's axis is tilted relative to the ecliptic plane.

smallest to largest planet orbit?

Earth, Moon's orbit, the Sun, Neptune's orbit

Why does Mars appear reddish in color?

It reflects most of the Sun's red light while absorbing most of its blue light.

What happens to Earth's axis as we orbit around the Sun over the course of each year?

It remains pointed in the same direction at all times.

What is special about the June solstice?

It's the day on which the Northern Hemisphere receives its most direct sunlight.

Earth has a relatively strong magnetic field, but Mars does not. Which of the following probably explains why Mars lacks a strong magnetic field today?

Its core is too cool for convection.

You discover an asteroid that orbits the Sun with the same 1-year orbital period as Earth. Which of the following statements must be true?

The asteroid's average (semimajor axis) distance from the Sun is 1AU.

As a comet orbits around the Sun, its maximum speed is twice its minimum speed. What can we say about its orbit?

The comet is twice as far from the Sun at aphelion as at perihelion.

Redshift

The greater the redshift, the faster the speed away from you.

Suppose that Mars had a higher surface temperature. How would its spectrum be different?

The peak in the infrared would be at shorter wavelength.

If you stood on a planet with four times the mass of Earth, and twice Earth's radius, how much would you weigh?

The same as on Earth.

Carbon dioxide in Mars's atmosphere produces _______ in the infrared portion of its spectrum.

absorption lines

Doppler effect

allows us to determine how fast Mars is moving toward or away from us.

Which of the following type of spectrum would you expect if you view star light that has passed through a cool cloud of interstellar gas on its way to Earth?

an absorption line spectrum

The sum of the number of protons and neutrons in an atom is called the

atomic mass number

Each chemical element has a unique

atomic number

The number of protons in an atom is called the atom's

atomic number

waxing crescent moon

-visible near western horizon about an hour after sunset -sets 2-3 hours after sun sets

Light received from a galaxy at the far end of the Local Supercluster was emitted roughly ____________.

10^8 years ago

Which one can be explained by Kepler's third law?

Venus orbits the Sun at a faster orbital speed than Earth.

Mercury

has a greater difference in temperature between its day and night sides than any other world.

neptune

has a large moon, Triton, that almost certainly once orbited the Sun independently.

earth

has a single moon that is surprisingly large compared to its planet.

venus

has a surface hot enough to melt lead as a result of an extremely strong greenhouse effect

Uranus

has an axis tilt that gives it very extreme seasons.

mars

has no surface liquid water today, but shows clear evidence of such water in the distant past.

If a hot gas cloud is moving toward us, the frequency of the emission lines will be

higher than those of a stationary gas cloud

The inner planets are small and rocky and the outer planets are mostly large and gaseous because

hydrogen compounds are more abundant than rocks and metals so that beyond the frost line the gravity of large ice planetesimals could capture the abundant light gases.

As a giant cloud of gas collapses due to gravity, you would expect its rate of rotation to

increase

saturn

is orbited by at least two geologically active moons: Titan and Enceladus.

Eris

is similar in size to Pluto and also considered a dwarf planet.

Most hydrogen atoms have only a single proton in their nucleus, so a hydrogen atom that also has one neutron is an ______ of hydrogen.

isotopes

As the solar nebula collapsed under its own gravity,

it heated up and spun up.

Why wasn't the Sun-centered model of Copernicus immediately adopted after he proposed it?

it was not noticeably more accurate than the old Ptolemaic model

Thermal radiation gets its name because __________.

its spectrum depends on the temperature of the object emitting it

A planet is discovered orbiting the star 51 Peg with a period of four days (0.01 years). 51 Peg has the same mass as the Sun. Mercury's orbital period is 0.24 years, and Venus's is 0.62 years. The average orbital radius of this planet is

less than Mercury's.

The Sun reaches the zenith (directly overhead) at midday ___________.

-on the equator only on the March and September equinoxes -everywhere within the tropics (between latitudes 23.5°N and 23.5°S) on two dates each year

What is true about the phases of the moon?

-the time between new moon and full moon is about two weeks - at new moon, the half of the Moon facing the Sun is fully illuminated -at new moon, we see only the "night" side of the Moon

Which of the following are the three key hallmarks of science?

- Modern science seeks explanations for observed phenomena that rely solely on natural causes. -Models must make testable predictions that will force us to revise or abandon the model if they do not agree with observations. -Science progresses through the creation and testing of models of nature that explain the observations as simply as possible.

Consider a planet orbiting another star that is very similar to our Sun. Assume the planet is about the size of Earth and has an Earth-like orbit around its star. Which of the following statements are true about the light coming from the star and planet?

- The star emits much more total light than the planet. - The star's spectrum peaks in visible light. -The planet emits virtually all its light as infrared light

waning crescent moon

- occurs about 3 days before new moon -visible near eastern horizon just before sunrise

What are four key features of our solar system that any theory of solar system formation must be able to explain?

-There are vast numbers of asteroids and comets. -Planets fall into two major categories. -There are a few notable "exceptions to the rules." -There are clear patterns to the rotation and orbits of large bodies in the solar system.

Which of the following statements about our solar system's terrestrial worlds are true?

-They are all made primarily of rock and metal. -Their interiors all have a core, mantle, and crust. -They are all of nearly the same age. Submit

Which of the following can you observe about Venus with the naked eye?

-Venus sometimes shines brightly in the eastern sky shortly before dawn -Venus sometimes shines brightly in the western sky shortly after sunset

Which of the following statements are true about summer compared to winter?

-You have more daylight and less darkness in summer. -Temperatures tend to be warmer in summer. -The Sun follows a longer and higher path through your sky in summer.

Which of the following represents a change from potential energy to kinetic energy?

A rock starting from rest on a high cliff, then moving faster and faster as it falls

Which object emits more infrared radiation?

A star that is the same size as the Sun but five times hotter

waning gibbous

A waning gibbous moon rises at about 9pm, reaches its highest point in the sky at about 3am, and sets around 9am

waxing crescent

A waxing crescent moon rises at about 9am, reaches its highest point in the sky at about 3pm, and sets around 9pm.

waxing gibbous

A waxing gibbous moon rises at about 3pm, reaches its highest point in the sky at about 9pm, and sets around 3am.

Why do the planets orbit the Sun (i.e. why don't they crash into the Sun)?

Although the planets experience a force of gravity from the Sun, since they are moving, their trajectories bend around the Sun rather than lead directly into the Sun.

Why do we essentially see the same face of the Moon at all times?

Because the Moon's rotational and orbital periods are equal.

The Sun rises and sets each day because

Earth rotates once each day

Suppose two comets, comet A and comet B, were orbiting the Sun, having the same average orbital radii. If comet A had a higher eccentricity than comet B, which comet would, during some portion of its orbit, have the highest orbital speed?

Comet A.

For the radial speed of an astronomical object to be determined, what must the object's spectrum contain?

Either absorption or emission lines

As seen from Earth, the sun appears to follow the annual path that we call the ______ around the celestial sphere

Eliptic

Where does the Sun remain above the horizon all day (never setting) on the December solstice?

Everywhere between the Antarctic Circle (latitude 66.5°S) and the South Pole

When is the Sun in the Northern part of the sky at noon for people who live on the equator?

From March 21 until Sep. 21

On your way to work about two hours after sunrise, you notice the moon setting. What phase is it in?

Gibbous

Which of the following best summarizes the reason we see phases of the Moon?

Half the Moon is always illuminated by the Sun, but the phase we see depends on how much of this half we are looking at from Earth.

Incandescent light bulbs emit thermal radiation because their filaments are heated to about 2500 Kelvin. LED light bulbs emit only at particular visible wavelengths. Why do incandescent bulbs require more energy to shine with the same amount of visible light as LED bulbs?

Incandescent bulbs emit most of their energy as infrared light.

How does the amount of heat released in a planet's interior by radioactive decay change with time?

It drops off with time.

If an astronomer claims to have discovered an object with a very eccentric orbit, which of the following best describes the orbital trajectory of the object?

It looks like a very squashed oval.

The earliest radio broadcasts on Earth were emitted about 100 years ago. Approximately where are these initial radio waves now? (Radio waves are a type of radiation, so they travel at the speed of light)

Just passing relatively local stars in our galaxy.

We expect a scientific theory to be able to make predictions that can be tested. Which of the following is a prediction of the nebular theory that has been verified by observations?

Many stars should have planets.

All of the following statements are true. Which one can be explained by Kepler's second law?

Mars moves faster in its orbit when it is closer to the Sun than when it is farther from the Sun.

Imagine Earth's identical twin planet "Farth" is twice as far away from the Sun as Earth is. Compared to the force of gravity the Sun experiences due to Earth, how strong is the force of gravity the Sun experiences due to Farth?

One-fourth as strong.

Two planets are observed going around a star. Planet Xoron has an orbital period that is twice as long as planet Krypton. Which planet has a shorter average orbital radius

Planet Krypton

Suppose object A has three times as the mass of object B. Identical forces are exerted on the two objects. Which statement is true?

The acceleration of object B is three times that of object A.

Suppose you go outside and look at three stars. Star A is blue, Star B is white, and Star C is red. Which star is the hottest and which star is the coldest?

Star A is the hottest and Star C is the coldest.

Suppose the Sun suddenly shrunk, reducing its radius by a half (but keeping its mass the same). The force of gravity exerted on Earth by the Sun would ____________.

Suppose the Sun suddenly shrunk, reducing its radius by a half (but keeping its mass the same). The force of gravity exerted on Earth by the Sun would ____________.

What is the cause of the lunar phases (i.e. why doesn't the Moon look the same every day)?

The Moon's orbit around Earth causes different amounts of the illuminated side of the Moon to be visible from Earth.

Suppose a parachutist is falling toward the ground, and the downward force of gravity is exactly equal to the upward force of air resistance. Which statement is true?

The velocity of the parachutist is not changing with time.

If a star is moving away from you at a constant speed, how do the wavelengths of the absorption lines change as the star gets farther and farther?

The wavelengths remain the same.

Two observers, one in northern Canada and the other in Australia, are looking at the Moon on the same day. The observer in Canada sees a Third Quarter Moon. What does the observer in Australia see?

Third Quarter Moon

If a star is moving away from you at constant speed, the absorption lines in its spectrum will

be redshifted (have wavelengths longer than those of an identical stationary star).

Suppose the solar nebula had been too warm for ices to condense anywhere. If a planet had still formed at Jupiter's location, it most likely would have

been similar in composition to Earth, with a much smaller mass than the real Jupiter.

Earth is slightly closer to the Sun in January than in July. How does the area swept out by Earth's orbit around the Sun during the 31 days of January compare to the area swept out during the 31 days of July?

both areas are the same

If the Earth did not have a tilt, the weather during June in Colorado would be ____________.

colder

If the Earth were tilted 45 degrees (rather than 23.5 degrees), winters in Colorado would be ____________.

colder

As the solar nebula collapsed, it became a disk because

collisions between particles made the particles go in more-or-less the same direction.

As a general rule, smaller planets __________ than larger planets.

cool more rapidly

Roughly what time of day is a Third Quarter Moon highest in the sky?

dawn

Suppose two objects are attracting each other gravitationally. If you double the distance between them, the strength of their gravitational attraction __________.

decreases by a factor of 4

An atom with more electrons than protons has a negative

electric charge

Which of the following are allowed orbital paths under gravity?

elliptical hyperbolic parabolic

Hot gas in Mars's upper atmosphere produces ________ in the ultraviolet portion of its spectrum.

emission lines

Suppose you see a moon that is half bright and half dark in your early evening sky. Then you are seeing a __________ moon.

first quarter

By how many orders of magnitude is the distance to the nearest stars greater than the orbital radius of Neptune?

four

the sun

generates energy deep in its core through the fusion of hydrogen into helium

Jupiter

has a famous storm known as the Great Red Spot.

When is the Sun highest in the sky at noon for people living in Sydney, Australia?

winter solstice (dec 21)

Suppose the solar nebula had cooled much more before the solar wind cleared away the remaining gas. In that case, the terrestrial planets likely would have ended up

with a higher abundance of hydrogen compounds and larger size.

If Earth's orbit were very eccentric, but the average distance from the Sun were still 1 AU, its orbital period

would still be one year