Astronomy 1010 Exam 2

The main greenhouse gases in the atmospheres of the terrestrial planets are...

Carbon dioxide and water vapor

Over the last 800,000 years, Earth's temperature has closely tracked...

Carbon dioxide levels in the atmosphere

Earth is composed of differentiated layers with distinctive attributes. Starting with the center and moving outward, indicate the proper sequence of the layers.

Center: - Solid core - Liquid core - Mantle - Crust - Atmosphere Exterior

After it was discovered, astronomers predicted Uranus's orbit using Newton's laws of motion and gravity, which had worked extremely well for all of the other planets. To their surprise, they found that their observations of Uranus's motion through the sky did not match their predictions. Which of the following would be the most logical next step?

Check for other previously undiscovered factors that might alter Uranus's orbit while still allowing it to obey Newton's laws of motion and gravity

During a space battle a tie fighter is approaching an x wing at 0.5c and fires a laser beam traveling at a speed c relative to the tie fighter. At what speed does the pilot of the x wing see the laser beam approach?

c, the speed of light

What is the driving mechanism behind sunspots, solar prominences and coronal mass ejections?

The suns magnetic field

If a radioactive element has a half-life of 10,000 years, what fraction of it is left in a rock after 40,000 years?

1/16

If a radioactive element A decays into radioactive element B in 1 half-life of 20 seconds, then after 40 seconds...

1/4 of element A will remain

Match the star mass with its lifetime as a protostar.

100 Msun = 10,000 10 Msun = 100,000 Msun = 10 mil 0.1 Msun = 100 mil

Particles at the very outer edge of Saturn's A Ring are in a 7:6 orbital resonance with the moon Janus. If the orbital period of Janus is 16 hours 41 minutes, what is the orbital period of the outer edge of Ring A?

14.30 hours

If the radius of an object's orbit is reduced by a factor of 3.00, then in order for angular momentum to be conserved, the velocity must increase by a factor of...

3.00

During a nuclear fusion process 5.3x10-28 kg of mass is converted to energy. How much energy is produced in this process?

4.77x10^-11 J

The obliquity of Uranus is 98°, creating seasonal effects much different from those experienced on Earth. If you were standing at the north pole on a planet with obliquity of 97.0 °, how far from the zenith would the Sun appear at the time of summer solstice? What would be the Sun's altitude (angular height from your horizon)?

7.0 degrees 83.0 degrees

A bar is a measure of atmospheric pressure, where one bar is equivalent to Earth's atmospheric pressure at sea level. Venus's atmosphere has a pressure of 92 bars. Water pressure in Earth's oceans increases by one bar for every 10 m of depth. How deep would you have to go to experience pressure equal to the atmospheric surface pressure on Venus?

920 m deep

A new star is forming inside this glowing cloud of gas. The dark band in the middle is made of a disk of thick dust, which obscures the light within it and hides the forming star from view. Newly forming stars are surrounded by gas and dust. Based on this observation, what is the most likely scenario for the formation of the Solar System?

A cloud of gas and dust collapsed into a flattened disk, within which the Sun and planets formed

An occultation occurs when...

A planet passes between Earth and a star

Space telescopes that exist in orbit above most of Earth's atmosphere are expensive, so they must therefore be supported with a very compelling motivation. If you were trying to justify funding for a space telescope in orbit around the Earth, which of the following would be the best argument to use?

A telescope could observe wavelengths of light that are not visible from the ground

Match the following properties of telescopes with their corresponding definitions.

Aperture: diameter Resolution: ability to distinguish objects that appear close together in the sky Focal length: distance from lens to focal plane Chromatic aberration: rainbow-making effect Diffraction: smearing effect due to sharp edge Interferometer: several telescopes connected to act as one

Saturn's bright rings are located within the Roche limit of Saturn. This supports the theory that these rings...

Are formed of moons torn apart by tidal stresses

The oxygen molecules in Earth's atmosphere...

Are the result of life

As a comet leaves the inner solar system, its ion tail points...

Away from the Sun

Scientist rely on electromagnetic waves to study many structures in our universe but sometimes electromagnetic waves cannot be used and scientist rely on gravitational effects. Which of the items listed can only be studied by its gravitational effects?

Black holes

If a large cloud of interstellar dust appears in the blue part of the visible spectrum what is most likely happening?

Blue light is being reflected from the dust in the interstellar cloud

List the layers of the sun from the core to the outermost layer.

Core - Radiative zone - convection zone - photosphere - chromosphere - corona

If the density of the Moon is 3.34 g/cm3, which layer of the Earth is it most similar to?

Crust

During the earliest stages of protostar formation when the dust and gas are being pulled to the center of the structure the primary source of energy that will drive all future processes comes from _______________.

Gravitational potential energy

Cameras that use adaptive optics provide higher spatial-resolution images primarily because...

Deformable mirrors are used to correct the blurring due to Earth's atmosphere

Differentiation refers to materials that are separated based on their...

Density

Which of the following mechanisms contribute significantly to the formation of planetary rings?

Destruction of a moon by tidal forces

Individual cloud layers in the giant planets have different compositions. This happens because...

Different volatiles freeze out at different temperatures

Rank the following events in the order that corresponds to the formation of a planetary system.

Earliest: - Gravity collapses a cloud of interstellar gas - A rotating disk forms and dust grains stick together by static electricity - Small bodies collide to form larger bodies - Primary atmospheres form - A stellar wind "turns on" and sweeps away gas and dust, removing primary atmospheres - Secondary atmospheres form Latest

Lava flows on the Moon and Mercury created large, smooth plains. We don't see similar features on Earth because...

Earth has plate tectonics that recycle the surface

Building effective detectors for particles or waves that scientists would like to study is a real challenge. Some are easily detected, while others are not. Rank the following items in order of increasing difficulty of detection.

East to detect: - Infrared photons - Neutrinos - Gravity waves Difficult to detect

Gravitational interactions with moon produce...

Fine structure within rings

A chunk of iron weighing a few kilograms flies into the inner Solar System, is captured by Earth's gravity, enters the atmosphere burning brightly, and lands on solid ground. Three different names apply to the different stages of its journey. Place them in order from first to last.

First stage: - Meteoroid - Meteor - Meteorite Last stage

Study the size difference of the gas giants as shown in the above image (distance from the Sun increases from left to right), and choose the best explanation below for your observations.

Gas giants decrease in size with increased distance from the Sun because the Solar Nebula was less dense farther out

CCD cameras have much higher quantum efficiency than other detectors. As a result, CCD cameras can...

Generate a signal from fewer photons

What force is reimagined as a curvature of space time in General relativity?

Gravitational force

Uranus and Neptune are different from Jupiter and Saturn in that Uranus and Neptune...

Have a higher percentage of ices in their interiors

Oort Cloud objects will only pass close to Earth and become comets if their orbits are...

Highly elliptical

For most of the sun's life the inward pull of gravity and the outward push of pressure are equal in strength at all points in the sun. What is this state called?

Hydrostatic balance

Match the atomic structure as an input to the proton proton chain fusion process or an output to the process.

Input: electron Output: Helium-4 atom

Gaseous planets:

Jupiter, Saturn, uranus, Neptune

The transit method preferentially detects...

Large planets close to the central star

Calculate the oblateness of the following giant planets and rank them from least to most oblate. The equatorial and polar diameters in 1000s of kilometers are:Planet 1: Equatorial diameter = 160; polar diameter = 145Planet 2: Equatorial diameter = 52; polar diameter = 48Planet 3: Equatorial diameter = 120; polar diameter = 114Planet 4: Equatorial diameter = 77; polar diameter = 72

Least oblate: - Planet 3 - Planet 4 - Planet 2 - Planet 1 Most oblate

Refraction is caused by...

Light changing speed and bending as it enters a new medium

The milky way galaxy is a barred spiral galaxy but the structure of the galaxy expands beyond the arms of the galaxy. A diagram of the galaxy is shown below. What is the structure denoted by E?

Magellanic cloud

List in order the stages of a low mass star beginning with the main sequence.

Main sequence - helium flash - horizontal branch - planetary nebular ejection - white dwarf

Match the stage in a high mass stars life with the element that is produced during that time.

Main sequence = helium Supergiant = silicon Supernova = silver

An active galactic nuclei can release an immense amount of energy in to the universe. What is the cause of the nuclei of a galaxy becoming active?

Material falling on to a supermassive black hole

Rocky planets:

Mercury, Venus, Earth, Mars, Ceres

In which type of interstellar cloud is star formation most likely to occur?

Molecular clouds

Earth's interior is heated by...

Radioactive decay and tidal effects

Whether a planet has an atmosphere or not depends on a number of factors: mass, temperature, composition of the crust, volcanic activity, and complex evolutionary processes.Rank the planets according to how well they retain their atmospheres, using the following criteria: • The planet that still maintains its primary atmosphere, ranks first. • The planet that lost its primary atmosphere but retains a dense secondary atmosphere, ranks second. • The planet that lost its primary atmosphere and retains a tenuous secondary atmosphere, ranks third. • The planet that retained neither its primary nor secondary atmospheres, ranks last.

Most succesful: - Jupiter - Venus - Mars - Mercury Least successful

The photons created in the core of the sun can take thousands of years to reach the surface as they interact with the dense matter. Scientist have successfully detected another product created in the core of the sun that can escape quickly and teach us about the fusion process. What is the name of this particle?

Neutrino

Uranus's orbit did not appear to behave according to Newton's laws of motion and gravity. The most likely culprit for Uranus's misbehaving orbit was the gravitational influence of another planet. Using Newton's laws, astronomers were able to calculate exactly where they would expect this still-undiscovered planet to be. When telescopes were pointed at this position, Neptune was seen. What does this imply?

Newton's laws have been verified by yet another test, so we should use them with high confidence until and unless they are falsified by future tests

You are riding in the passenger seat of a car traveling at 10 mph when you throw a football to someone in the bed of a truck that is driving in front of the car. If you throw the football with a speed of 10 mph relative to the car how fast does someone on the side of the road see the football traveling?

Not 10mph

What is the primary indication that stars in the main disc of our galaxy have had many more generations of star formation and explosion than stars in the globular clusters of our galaxy?

Not color of the stars

What best describes the path a high mass protostar takes on the Hertzprung-Russell diagram as it approaches the main sequence?

Not diagonal

The Hubble tuning fork is used to classify galaxies and is shown below. What is the name for galaxies found in the region labeled A?

Not elliptical

What is required for a Type Ia supernova to occur?

Not extremely high mass single star

The Hayashi track of low mass stars is possible because the surface temperature of the star is kept constant in part due to an atomic blanket that is added when the surface cools and removed when the surface heats. What atomic structure creates this blanket effect?

Not neutral He atoms

Scientists use a variety of methods to determine the approximate distance to various celestial objects. What is the most likely method used to determine the distance to distant galaxies?

Not spectroscopic parallax

What aspect of a modern car relies on relativistic principles?

Not the speedometer when moving at highway speeds

The motion of stars in a galaxy determines what the galaxy looks like. In an elliptical galaxy the stars move in _____. In a spiral galaxy the stars in the center bulge move in _____ and the stars in the spiral arms move in _____.

Random directions Random directions; the same direction around the center

Why does the fusion process only happen in the core of the Sun during its main sequence life?

Only in the core are the temperature and density high enough to fuse hydrogen

Ganymede, Europa, and Io share a 4:2:1 resonance in their orbits around Jupiter. If Io's orbital period is 1.77 days, what are the orbital periods of Europa and Ganymede? Note that Io is the innermost of the three moons, and Ganymede is the outermost.

Orbital period of Europa: 3.54 days Orbital period of Ganymede: 7.08 days

The composition of the protoplanetary disk varies with distance from the protostar due to temperature. Starting with those closest to the protostar, place these materials in order based on where they can be found predominantly in their solid states.

Order of Planetary Formation Closest: - Iron, silicates, carbon - Water - Methane, ammonia, CO Farthest

Suppose an earthquake occurs on an imaginary planet. Scientists on the other side of the planet detect primary waves but not secondary waves after the quake occurs. This observation suggests that

Part of the planet's interior is liquid

Rock/ice mixture planets:

Pluto, Eris

The following chemicals either have been or are now part of terrestrial planet atmospheres. Determine whether each is found in either a planet's primary or secondary atmosphere.

Primary atmosphere: helium, hydrogen Secondary atmosphere: carbon dioxide, nitrogen, oxygen, water

What is the name of the primary fusion process that fuses hydrogen in to helium in a low mass star?

Proton-proton chain

What is the primary mode of energy transfer from a camp fire to your hand if you hold your hand a few feet to the side the fire?

Radiation

Sort each of the five terrestrial bodies into the appropriate category based on the type of atmosphere it currently retains, if any.

Secondary atmosphere: Venus, Mars, Earth No atmosphere: Mercury, Earth's moon

Asteroids are...

Small rock and metal objects orbiting the Sun

Which of the following is the biggest disadvantage of putting a telescope in space?

Space telescopes are much more expensive than similar ground-based telescopes

Imagine that a star-forming cloud collapses but retains all of its mass in a single blob. In order to conserve angular momentum, the cloud must...

Spin faster

Volcanoes on Enceladus affect the E ring of Saturn by...

Supplying ring particles

The chemical compositions of Jupiter and Saturn are most similar to those of...

The Sun

Zonal winds on the planets are stronger than those on the terrestrial planets because...

The giant planets rotate faster

Scientists know the history of Earth's magnetic field because...

The magnetic field freezes into rocks, and plate tectonics spreads the rocks out

Why do we find rocky material everywhere in the Solar System, but large amounts of volatile material only in the outer regions?

The outer regions of the Solar System are cooler

Deep in the interiors of the giant planets, water is still a liquid even though the temperatures are tens of thousands of degrees above the boiling point of water. This can happen because...

The pressure inside the giant planets is so high

What is constant in all frames of reference in special relativity?

The speed of light

Imagine that you are observing a car that is out of control and spinning on the ice on the highway. The car suddenly stops spinning and starts spinning in the other direction as it slides down the highway. In order for this to happen, what must have taken place?

There must have been external forces acting on the car - for example, the spinning car struck another car

Why are Ganymede and Callisto geologically dead while the other two Galilean moons of Jupiter are active?

They are farther from Jupiter

Less massive molecules tend to escape from an atmosphere more often than more massive ones because...

They are moving faster

Kuiper Belt objects (KBOs) are actually comet nuclei. Why do they not display comas and tails?

They are too far from the Sun

This chapter deals with leftover planetesimals. What became of most of the others?

They became part of larger bodies

Why are dwarf planets considered planets despite being smaller than some moons?

They do not orbit a body other than the Sun

Convection in the _____ causes weather on Earth

Troposphere

The ozone layer protects life on Earth from...

Ultraviolet radiation

Which of the giant planets has the most extreme seasons?

Uranus

Neptune's existence was predicted because...

Uranus did not obey Newton's laws of motion

Which of the following worlds does not show evidence of the current presence of liquid or frozen water?

Venus

Venus is hot and Mars is cold primarily because...

Venus has a much thicker atmosphere

Under what lighting conditions are the tiny dust particles, found in some planetary rings, best observed?

Viewed from the shadowed side of the planet, looking toward the Sun

lo has the most volcanic activity in the Solar System because...

its interior is tidally heated as it orbits Jupiter

The radial velocity method preferentially detects...

large planets close to the central star

Because of its small size, Mercury has lost most of its internal heat from its formation and is nearly geologically dead. Io is smaller than Mercury, but it is the most geologically active object in the Solar System, with volcanic eruptions constantly repaving its surface. Of the four large Galilean moons orbiting Jupiter, Io is the closest to the planet. Considering Io's size and location in the Solar System, what is the most likely reason for Io's high level of geological activity?

lo's proximity to Jupiter provides a current source of internal heat