more questions

Why do sunspots appear dark in pictures of the Sun?

They actually are fairly bright but appear dark against the even brighter background of the surrounding Sun

How do we think the "hot Jupiters" around other stars were forme

They formed as gas giants beyond the frost line and then migrated inward

What do meteorites reveal about the solar system?

They reveal that the age of the solar system is approximately 4.6 billion year

The overall fusion reaction by which the Sun currently produces

energy is 4 H =1 He + energy

CO2, H2O, are

greenhouse gases

Which property of our solar system does a formation theory NOT need to explain

he presence of life on Earth

Uranus and Neptune have methane clouds but Jupiter and Saturn do not. Which factor explains why?

Temperatures on Jupiter and Saturn are too high for methane to condense.

How do scientists know that the majority of meteorites come from the asteroid be

The spectra of some meteorites are similar to the spectra of asteroids in the asteroid bel

Most meteorites are

rocky and primitive

In order to have a comet named after you, you have to be one of

the first three discoverers who report it to the International Astronomical Union (IAU).

Ganymede is

the largest moon in the solar system

How much energy does Jupiter emit compared with how much it receives from the Sun?

It emits twice as much.

How does the largest asteroid, Ceres, compare in size to other solar system worlds?

It is about half the size of Pluto

Where are the Trojan asteroids located?

along Jupiter's orbit, 60degree ahead of and behind Jupiter

Falling stars and shooting stars are simply other names for

meteors.

Which is closest to the average distance between asteroids in the asteroid belt

1 million km

What is the typical size of comets that enter the inner solar system?

10 km

How many more times is the atmospheric pressure in Jupiter's core greater than the atmospheric pressure at the earth's surface?

100 million

Jupiter's orbital distance is roughly 5 AU. How many times brighter would the Sun have to be for Europa to receive the same solar flux that we currently receive on Earth (1380W/m2)?

25 times brighter

the average temperature of the surface of the Sun is

6,000 K

What is the Sun made of?

70 percent hydrogen, 28 percent helium, 2 percent other elements

Suppose a solar system has a star that is four times as massive as our Sun. If that solar system has a planet the same size as Earth orbiting at a distance of 1 AU, what is the orbital period of the planet? Explain.

Again, Newton's version of Kepler's 3rd Law is PEarth2 = aEarth3 / M(solar masses). Here, M=4. So P2 = a3 / 4 = (1 AU) 3 / 4 = 0.25. P= √0.25 = 0.5 years

How do the jovian planet interiors differ?

All have cores of about the same mass, but differ in the amount of surrounding hydrogen and helium.

b) If the United States obtained all its energy from oil, how much oil would be needed each year

Annual US energy consumption / Energy released by burning 1 liter of oil = 1020 J / 1.2*107 J = 8.3*1012 liters of oil

Why do asteroids and comets differ in composition?

Asteroids formed inside the frost line, while comets formed outside.

What is planet's orbital distance? Mass of star is the same as Sun, orbital period is 63 days.

Because planet is going around an object that is the same mass as the Sun, the more simple Kepler equation (P2 = a3) can be used. P2 = a3 P = 63 days = 0.172 years a = P2/3 = (0.172 years)2/3 = 0.309 AU

According to Kepler's third law, (b) Jupiter orbits the Sun more quickly than Saturn.

Because the semimajor axis is smaller, the orbital period P = a3/2 will be smaller

Which of the following is/are NOT caused by orbital resonance

Breaking of small Jovian moons to form ring materials.

What did Nicholas Copernicus, Tycho Brahe, Johannes Kepler, andGalileo Galilei each contribute to astronomy?

Copernicus published work describing the Sun-centered solar system model. Brahe made what is generally considered the best set of naked-eye observations ever made that enabled Kepler to discover the laws of planetary motion. Kepler, Brahe's apprentice, discovered the basic laws of planetary motion. Galileo:Amongst his many accomplishments as arguably the greatest scientist of his time, Galileo was the first to use the telescope (he did not invent it) to take observations of the heavens that sealed the case for the Sun-centered solar system (e.g., Venus's phases, Jupiter's moons).

If the Sun were replaced by a black hole of the same mass, what would happen to Earth's orbit?

F = (GM1M2)/d2 The law of gravity depends on only the following: 1] the Universal Gravitation constant, G, which will not be affected. 2] the masses of both the Sun/black hole and Earth. 3] the distance between the Sun/black hole and Earth Because the mass of the black hole will be the same as the mass of the Sun, and Earth will not start at a different orbital distance when the change occurs, the correct answer must be (c) Earth's orbit would not change.

What is the orbital period of the planet?

For this problem, we must use Newton's form of Kepler's Third Law. P2 = [(4pi2)/G(M1 + M2)]*a3 Mass of star (M1) is 4 times the mass of the Sun. M1 = 4*(1.98892 x 1030 kg) Planet (M2) is same mass as Earth. M2 = 5.9742 x 1024 kg (Mass of planet << Mass of Sun, can be neglected) The planet is orbiting at 1 AU. a = 1 AU = 1.496 x 1011 m The gravitation constant G is 6.67 x 10-11 m3 /kg*s2 P = sqrt([(4pi2)/G(M1)]*a3) P = sqrt([7.44 x 10-20 s2/m3] * [1.496 x 1011 m]3) = 1.58 x 107 s = 182.9 days SIMPLER ANSWER: Think of the mass as 4Msun. Then (4pi2)/G(Msun) = 1 and the new equation is P2 = a3/4 where P is in years and a is in AU. P = sqrt((1 AU)3/4) = sqrt(1/4) = ½ year (note: ½ years = 182.5 days)

How do we know how old the Earth is

From radioactive dating of rocks and meteorite

What is the most important reason why an icy moon is more likely to be geologically active than a rocky moon of the same size?

Ice has a lower melting point than rock.

The most volcanically active body in our solar system is

Io

What is the solar wind?

It is the name we give to the gas (or plasma) particles flowing outward from the surface of the Sun into the solar system.

Why doesn't Venus have seasons like Mars and Earth do

Its rotation axis is nearly perpendicular to the plane of the Solar Syste

Why do Uranus and Neptune have blue methane clouds but Jupiter and Saturn do not?

Methane does not condense into ice in the warmer atmospheric temperatures of Jupiter and Saturn.

How does the strength of Jupiter's magnetic field compare to that of Earth's magnetic field?

Jupiter's magnetic field is about 20,000 times as strong as Earth's.

Which living organisms most resemble the common ancestor of all life according to genetic testing

Large impacts fractured the Moon's lithosphere, allowing lava to fill the impact basins

Imagine another solar system, with a star of the same mass as the Sun. Suppose there is a planet in that solar system with a mass twice that of Earth orbiting at a distance of 1 AU, what is the orbital period of this planet? Explain

Making the approximation MPlanet << MStar, Newton's version of Kepler's 3rd Law tells us PPlanet2= aPlanet3 / MStar (solar masses). Since the mass of the star hasn't changed in this problem, M=1 and P = a3/2 = (1 AU) 3/2 = 1 year.

What is the circumference of Nearth?

On the equinox, the sun is directly overheard in the city of Nyene, located 1000 km due north of Alectown, and on the equinox in Alectown, the altitude of the sun is 80°. Angle from the zenith = 90° - altitude = 90° - 80° = 10° (Angle found above is the latitude difference between Nyene and Alectown) Nearth's circumference = (360° / latitude difference) * distance between citiesCircumference = (360° / 10°) * 1000 km = (36*1000 km) = 36,000 km

(a) What is the mass of the Earth? Moon's period of orbit is 27.3 days, and semi-major axis is 384,000 km. Can neglect mass of Moon (Mass of Moon << Mass of Earth)

P2 = [(4pi2)/G(M1 + M2)]*a3 = [(4pi2)/G(M)]*a3 P = 27.3 days = 2.36 x 106 seconds a = 384,000 km = 3.84 x 108 m The gravitation constant G is 6.67 x 10-11 m3 /kg*s2 Solve for M: M = [(4pi2)/(G*P2)]*a3 = [0.106 kg/m3] * (3.84 x 108 m)3 = 6.02 x 1024 kg

What is the mass of Jupiter? Io orbits Jupiter every 42.5 hours, at an average distance of 422,000 km. Can neglect mass of Io (Mass of Io << Mass of Jupiter)

P2 = [(4pi2)/G(M1 + M2)]*a3 = [(4pi2)/G(M)]*a3 P = 42.5 hours = 1.53 x 105 seconds a = 422,000 km = 4.22 x 108 m The gravitation constant G is 6.67 x 10-11 m3 /kg*s2 Solve for M: M = [(4pi2)/(G*P2)]*a3 = [25.3 kg/m3] * (4.22 x 108 m)3 = 1.90 x 1027 kg

Halley's comet orbits the Sun every 76.0 years and has an orbital eccentricity of 0.97. (a) Find its average distance by using Kepler's Third Law (applies here because Halley's comet orbits the Sun).

P2 = a3 P = 76.0 years a = P2/3 = (76.0 years)2/3 = 17.94 AU

What Mars mission will be landing on May 25, 2008 and will dig a trench into (hopefully) ice-rich soil?

Phoenix Mars Lande

Why is astrology a pseudoscience and astronomy is not? Explain.

Pseudoscience means "false science". To be science, a subject must conform to the hallmarks of science listed in the text: (summed up) being able to test ideas of how natural processes work that can, in principle, be disproven. Astrology seeks to explain how the positions of astronomical objects affect our lives, yet such forecasts do not stand up to scrutiny; no causual relationship has ever been established.

Most rocks on the Moon's surface are older than those on the Earth's surface. The best evidence for this is:

Radioactive dating of lunar samples shows that they are olde

A small comet was discovered with an orbital eccentricity of e=0.6 and a semi-major axis of 46 AU. It passed closest to the Sun in 2010. When (what year) will it make its next close passage?

Since the object is orbiting the Sun and we want to express the answer in years, we can use the simple form of Kepler's third law: p 2 years = a 3 AU ) pyears = (46 AU)3/2 = 312 years The next passage of the comet will be in 2010 + 312 = 2322 .

How is the sunspot cycle directly relevant to us here on Earth?

Solar flares and other activity associated with the sunspot cycle can disrupt radio communications and knock out sensitive electronic equipment.

What is the Great Red Spot?

The Great Red Spot is a long-lived, high-pressure storm on Jupiter.

Which is not an essential requirement for life as we know

The ability to breathe oxygen The ability to make energy from sunlight, or to eat things that

How can we best observe the Sun's chromosphere and corona?

The chromosphere is best observed with ultraviolet telescopes and the corona is best observed with X-ray telescopes.

c) Compare the Sun's annual energy output to the energy released by a supernova.

The energy released by a supernova is ~1044 J / 1034 J = 1010 times larger

Use the data in Table 4.1 to answer each of the following questions. a) Compare the energy of a 1‐megaton H‐bomb to the energy released by a major earthquake

The energy released by an earthquake is 2.5*1016 J / 4*1015 J =6.25 times larger

If Earth were twice as far from the Sun, what would the force of gravity between them be?

The equation needed here is the universal law of gravitation, discovered by Newton:F = (GM1M2)/d2 (Note: the force depends on the inverse of distance squared.) Current force of gravity on Earth: F1 = (GM1M2)/d2 "New" force of gravity on Earth: F2 = (GM1M2)/(2d)2 F2 = (F1)/4, therefore the answer is (c) one-quarter as strong.

What is true about the rotation of a solid disk?

The period of rotation is the same on every point on the dis

Why does the plasma (ion) tail of a comet always point away from the Su

The solar wind electromagnetically "blows" the ions directly away from the Sun

Where does Halley's comet spend most of its time?

Use Kepler's Second Law: As a planet moves around its orbit, it sweeps out equal areas in equal times. So when it is closest to the Sun, the comet will be moving fastest, and conversely when it is furthest from the Sun, the comet will be moving the slowest. Therefore, Halley's comet must spend most of its time at aphelion, when it is furthest from the Sun, because it moves the slowest at that point.

Life on Earth originated from

We don't know for sure

What observations characterize solar maximum?

We see many sunspots on the surface of the Sun

When visiting another planet, (b) your mass would be the same as on Earth, but your weight would be different

Weight depends on the strength of gravity.

The recently discovered Eris, which is slightly larger than Pluto, orbits the Sun every 560 years. What is its average distance (semimajor axis) from the Sun? How does its average distance compare to that of Pluto?

a = P2/3 = 5602/3 = 67.9 AU. This is further from the Sun than Pluto, which has a semimajor axis of ~40AU.

An icy leftover planetesimal orbiting the Sun is

a comet.

How thick are Saturn's rings from top to bottom?

a few tens of meters

What is a meteorite?

a fragment of an asteroid from the solar system that has fallen to the earth's surface

The four Galilean moons around Jupiter are

a mixture of rock and ice, with the ice fraction increasing with distance from Jupiter.

What is the hydrosphere?

a name for the liquid and frozen water on Earth's surface

Titan moon has

a thick atmosphere.

. Problem 3‐40 (2 pts). The recently discovered object Sedna orbits our sun beyond Pluto, at an average distance of 509 AU. What is its orbital period?

a=509 AU, P2 = a3. P = a3/2 = 5093/2 = 11,480 years

Pluto was discovered

about 70 years ago

What are coronal holes?

areas of the corona where magnetic field lines project into space, allowing charged particles to escape the Sun, becoming the solar wind

Comets are

balls of ice and dust.

How do astronomers think Jupiter generates its internal heat

by contracting, changing gravitational potential energy into thermal energy

How do astronomers think Jupiter generates its internal heat?

by contracting, changing gravitational potential energy into thermal energy

the Sun generates energy today

by nuclear fusion

What drives the motion of the continental plates on Earth?

convection cells in the mantle

Which of the following methods has led to the most discoveries of massive planets orbiting near their parent stars?

detecting the gravitational effect of an orbiting planet by looking for the Doppler shifts in the star's spectrum

Europa moon is considered likely to have a

deep, subsurface ocean of liquid water

Europa thought to have a

deep, subsurface ocean of liquid water

If the Moon were closer to the Earth, high tides would be

higher than they are now. As the Moon gets closer, the gravitational force of attraction increases. The difference in the force of attraction between different parts of Earth and the Moon will also increase.

The core of the Sun is

hotter and denser than the surface.

Why does Jupiter have several distinct cloud layers?

ifferent layers represent clouds made of gases that condense at different temperatures.

When do comets generally begin to form a tail?

inside of Jupiter's orbit

the size of the largest asteroid

is 1,000 km

The combined mass of all the asteroids in the asteroid belt is

less than that of any terrestrial planet.

Which of the following lists the ingredients of the solar nebula from highest to lowest percentage of mass in the nebula?

light gases (H, He), hydrogen compounds (H2O, CH4, NH3), rocks, metal

the most abundant gas in Titan's atmosphereis

nitrogen

the Sun loses 4 million tons of its mass through

nuclear fusion per second.

If Earth were twice as far from the Sun, the force of gravity attracting Earth to the sun would be

one‐quarter as strong. Gravity follows an inverse square law in proportion to distance.

Which living organisms most resemble the common ancestor of all life according to genetic testing

organisms living deep in the oceans around seafloor volcanic vents and in hot spring

Halley's Comet. Halley's Comet orbits the Sun every 76.0 years and has an orbital eccentricity of 0.97. Find its average distance from the Sun (semimajor axis). Find its perihelion and aphelion distances.

p 2 years = a 3 AU ) aAU = (76 yrs)2/3 = 17.9 AU Perihelion distance = a(1 − e) = 17.9 AU(1 − 0.97) = 0.5 AU Aphelion distance = a(1 + e) = 17.9 AU(1 + 0.97) = 35.3 AU

What are the spokes in Saturn's rings?

particles of dust suspended above the rings by magnetic forces

Which layer of the Sun do we normally see?

photosphere

) The phase of matter in the Sun is

plasma.

What process has shaped Earth's surface more than any other?

plate tectonics

the plasma tail of a comet

points most directly away from the Sun

Overall, Jupiter's composition is most like that of

the Sun.

Mars has an atmosphere that is almost entirely carbon dioxide.Why isn't there a strong greenhouse effect keeping the planet warm?

the atmosphere on Mars is too thin to trap a significant amount of hea

Meteorites can come from

the cores of asteroids. ancient lava flows. the Moon. Mars.

The nebular theory of the formation of the solar system successfully predicts all but one of the following. Which one does the theory not predict?

the equal number of terrestrial and jovian planets

When is/was gravitational contraction an important energygeneration mechanism for the Sun?

when the Sun was being formed from a collapsing cloud of gas