Astronomy Exam 2

The most likely models of the planet Mercury indicate that more than half the planet may be composed of:

metals

Chunks of solid material that survive passing through the Earth's atmosphere and are found on the Earth's surface are called

meteroites

The bluish color that makes the atmosphere of Neptune so beautiful to the human eye is caused by the interaction of sunlight with what gas?

methane

The lakes found in the north polar region of Titan are filled with liquid

methane

The upper clouds in the atmosphere of Neptune are composed of:

methane

Which substance plays the same role on Titan as water does on Earth (existing as gas, liquid, and solid)?

methane

lava

molten rock above ground

magma

molten rock underground

prograde

moon orbits in the same direction the planet spins

convection

movement caused within a gas or liquid by the tendency of hotter, and therefore less dense material, to rise and colder, denser material to sink under the influence of gravity, which consequently results in transfer of heat

The largest planet in the solar system (by mass) is

Jupiter

How does jupiter's distance to the sun compare with Earth's distance to the sun?

Jupiter is about 5 times farther from the sun than Earth

Which of the following statements about the seasons on Jupiter is correct?

Jupiter's axis is hardly tilted so it has no real seasonal variations

Why do astronomers today think that we have an asteroid belt and not a planet between Mars and Jupiter?

Jupiter's gravity prevented material in that zone from getting together

Between 1992 and today, astronomers using large telescopes have discovered many icy pieces that orbit in the same region as the orbit of Pluto. These are believed to be members of the

Kuiper belt

Venus: no pattern Earth: obvious pattern Mars: Maybe a pattern?

Look at the pictures of volcanoes on Venus, Earth, and Mars. What kind of patterns do you see?

slower

Looking at the other picture, would expect Pandora to be moving faster or slower than the particles in the F ring?

Faster

Looking at the other picture, would you expect Prometheus to be moving faster or slower than the F ring particles?

The spacecraft that sent back the most detailed radar images of Venus and showed us features as small as a football field is:

Magellan

About how big is Mars compared to Earth?

Mars is about half the size of Earth

Three kinds of worlds are round in our solar system. Which of the following is NOT a type of world that is typically round?

Minor planet (asteroid)

Saturn's rings

Most of Saturn's rings are within its Roche Limit -They are 99% water ice - Perhaps caused by comets that came too close to the planet? Or a small icy moon?

discovery stories - Jupiter and Saturn

Naked eye planets, seen since forever

The first human being to step out onto the surface of another world was:

Neil Armstrong

Which planet in the solar system has the longest year and orbits the most slowly?

Neptune

The tallest mountain on a terrestrial world is:

Olympus Mons (Mt. Olympus) on Mars

Which planet or dwarf planet in our solar system has the biggest moon relative to its own size? Not the biggest moon in terms of miles, but biggest compared to the size of the planet it orbits.

pluto

The person who really publicized the idea of canals on Mars and impressed it on the public mind was:

Percival Lowell

Jupiter mission

Pioneer 10 -1973 Pioneer 11 - 1974 Voyager 1 - 1979 Voyager 2 - 1979 Ulysses - 1992, 2000 Cassini - 2000 New Horizons - 2007 Galileo - 1995 - 2003

Saturn Missions

Pioneer 11 - 1979 Voyager 1 - 1980 Voyager 2 - 1981 Cassini - 2004-2017 Huygens Probe landed on Titan in 2005

Jupiter doesn't have seasons, because its axis of rotation is not tilted significantly. (true/false)

True

What would happen if there were no greenhouse gases?

UV, visible, and infrared light from the sun would pass completely through the atmosphere.

The planet that orbits "on its side" (i.e. has its rotation axis parallel to the plane of its orbit) is:

Uranus

prominences

Usually form over sunspots Can extend out into the corona

The spacecraft that soft-landed successfully on the surface of Venus (and briefly sent back pictures while sitting in that destructive environment) were called

Venera

Of the following planets, which has NO satellites (moons)?

Venus

One of the best ways to learn more about a world is to have samples from its surface to analyze in our laboratories. From which of the following worlds do we NOT yet have a sample to analyze here on Earth?

Venus

Which of these worlds is the most active geologically? Venus, the Moon, Mercury, or Mars

Venus

Which planet in the solar system rotates the most slowly (has the longest "day")?

Venus

Magnetic field of Venus and Mars

Venus has no magnetic field of its own. • Mars also has no magnetic field • but it has magnetized rocks, suggesting that it did have a magnetic field a long time ago

There was a pair of spacecraft whose components both orbited the planet Mars and landed on its surface in 1976. These spacecraft were called:

Viking

Uranus mission

Voyager 2 - 1986

Which of the following statements about the tails of comets is FALSE?

a comet always has a nice long tail, even when it is far from the Sun

Near-Earth object (NEO)

a comet or asteroid whose path intersects the orbit of Earth

solar wind

a flow of hot, charged particles leaving the Sun -comes primarily from "holes" in the corona. It is made up of charged particles, mostly protons and electrons.

bar

a force of 100,000 Newtons acting on a surface area of 1 square meter; the average pressure of Earth's atmosphere at sea level is 1.013 bars

greenhouse gas

a gas in an atmosphere that absorbs and emits radiation within the thermal infrared range; on Earth, these atmospheric gases primarily include carbon dioxide, methane, and water vapor

plasma

a hot ionized gas

Astronomers believe that Jupiter's strong magnetic field is caused by

a huge layer of metallic hydrogen inside Jupiter

The Red Spot of Jupiter is:

a large cyclonic storm or hurricane located in the southern hemisphere of Jupiter

These days the theory of the Earth's Moon's origin that best fits with the facts we have about the Moon is:

a large object hit the Earth and the collision produced a filament of material that condensed to make the Moon

prominence

a large, bright, gaseous feature that appears above the surface of the Sun and extends into the corona

Lagrange points

points in space where the planet's gravity and the star's gravity add up in a special way -trojan asteroids are at L4 and L5 - stable orbits in front of and following Jupiter -James Webb telescope is at Earth's L2

What does your above answer say about the interior of jupiter?

probably a liquid core

radioactivity

process by which certain kinds of atomic nuclei decay naturally, with the spontaneous emission of subatomic particles and gamma rays

dust tail

broad, curved, made of microscopic dust particles

Astronomers estimate that the runoff channels seen on Mars must be at least 3.9 billion years old. How do they estimate ages like this?

by counting impact craters in the regions containing these channels

Astronomers estimate that the plains of Venus are only about 500 to 600 million years old. How do they estimate dates like this?

by counting the craters visible on the surface and comparing crater counts to other worlds

Using radar waves reflected from Venus' surface, astronomers have determined that Venus takes about 24 hours to rotate on its axis. (true/false)

false

Using telescope on Earth, we can't make out any features on the surface of Mars. (true/fasle)

false

Venus and Mars are roughly identical in mass. (true/false)

false

While NASA has launched a lot of missions toward Mars, it's had a lot of bad luck; no spacecraft has landed successfully on Mars since the 1970s. (true/false)

false

rotation of the sun

faster towards the middle because its made up of gas

The image shown here depicts Jupiter with aurorae around its north pole. What is this evidence of?

jupiter's intense magnetic field

sunspot

large, dark features seen on the surface of the Sun caused by increased magnetic activity

In addition to hundreds of smaller objects they have been discovering in the Kuiper Belt recently, astronomers were surprised to find

larger bodies, with sizes as big as Pluto (now called dwarf planets)

Is more energy absorbed by Earth's surface coming from - light from the sun or - light from the atmosphere?

light from the atmosphere

aurora

light radiated by atoms and ions in the ionosphere excited by charged particles from the Sun, mostly seen in the magnetic polar regions

meteor shower

many meteors appearing to radiate from one point in the sky; produced when Earth passes through a cometary dust stream

asteroid belt

the region of the solar system between the orbits of Mars and Jupiter in which most asteroids are located; the main belt, where the orbits are generally the most stable, extends from 2.2 to 3.3 AU from the Sun

granulation

the rice-grain-like structure of the solar photosphere; granulation is produced by upwelling currents of gas that are slightly hotter, and therefore brighter, than the surrounding regions, which are flowing downward into the Sun

c ring particles

the rings of saturn are made up of millions of icy chunks. as they orbit saturn, they follow kepler's laws. looking at A, B, C, rings, which set of particles will be moving the fastest?

Halley's Comet was given that name because Edmond Halley was

the scientist who pointed out that the orbit of the comet was such that it should return every 76 years or so

sunspot cycle

the semiregular 11-year period with which the frequency of sunspots fluctuates

Astronomers call the vast, rotating cloud of vapor and dust from which the solar system formed:

the solar nebula

nucleus (of a comet)

the solid chunk of ice and dust in the head of a comet

spring tides

these strong tides occur during the new and full moons, when the gravitational force of the sun and moon pull together on the Earth

Neap tides

these weak tides occur when the gravitational forces of the Sun and moon are perpendicular

What is one important way in which both the Moon and Mercury are different from Earth?

they do not have an atmosphere

Which of the following is NOT a way that Jovian planets can be distinguished from terrestrial planets?

they have many more craters from collisions that happened early in solar system history

The European Huygens probe soft-landed on Saturn's moon Titan, becoming the first human craft to land on an outer-solar-system moon. (true/false)

true

The Oort cloud is a reservoir of icy pieces much further out from the Sun that the orbits of Pluto, Eris, or the members of the Kuiper Belt. (true/false)

true

The bright features seen on Ceres appear to be salt deposit, possibly from an underground ocean that occasionally erupted to the surface. (true/false)

true

The day on Mars is about 37 minutes longer than the day on Earth. (true/false)

true

The different compositions of the inner and outer planets can be explained as the result of differing temperatures in the solar nebula. (true/false)

true

The dwarf planet Pluto is so far away that we did not have any clear images of its surface until the New Horizons spacecraft flew by it in 2015. (true/false)

true

The largest asteroid, Ceres, was discovered in 1801 and at first thought to be a planet. (true/false)

true

The most common element found in the planet Jupiter is hydrogen. (true/false)

true

The orbits of Pluto and Charon are synchronized, so that Charon always keeps the same face toward Pluto and Pluto always keeps the same face toward Charon. (true/false)

true

The surface gravity on Mars is about 38% the surface gravity on Earth. (true/fasle)

true

The surface of Venus is hotter than the temperatures in your home oven. (true/false)

true

The time it takes Venus to rotate once on its axis is greater than the time it takes to make one orbit around the Sun. (true/false)

true

The two planets whose composition most resembles our Sun are Jupiter and Saturn. (true/false)

true

Using visible light, you can't generally see the surface features of Venus from space. (true/false)

true

When the Galileo spacecraft flew by the asteroid Ida, it discovered that Ida was orbited by a smaller asteroid (which would then be called its moon.) (true/false)

true

How do astronomers know that the age of the solar system is about 4.5 billion years old?

radioactive dating of the primitive meteorites indicates they have that age (since they are left-over building blocks of the solar system)

The lunar highlands are made mostly of rocks that

rose to the top as the Moon cooled from a molten state early in its history

One way to find a new meteorite is to:

search the area beneath or close to the point where a bright fireball was seen to burn out

Olympus mons is a volcano on Mars. This volcano is about 25 km tall and 600 km wide. What kind of volcano is this likely to be?

shield volcano

meteoroid

smaller than a meteor - a piece of a meteor

As a cool gas cloud collapses to form a star and planetary system, it

speeds it up its rotation and flattens

Most of the meteorites that hit the earth are

stony

ion tail

straight, made of ionized particles. Sometimes bluish

Astronomers now believe that the differences in composition among the planets reflect what characteristic in the early solar system?

temperature

mantle

the largest part of Earth's interior; lies between the crust and the core

stratosphere

the layer of Earth's atmosphere above the troposphere and below the ionosphere

One way in which Mars closely resembles the Earth is:

the length of its day (period of rotation)

highlands

the lighter, heavily cratered regions of the Moon, which are generally several kilometers higher than the maria

What formation or formations are evidence that the planet Mercury may have shrunk (gotten a bit smaller) as it cooled?

the long scarps or cliffs

Troposphere

the lowest level of Earth's atmosphere, where most weather takes place

The ages of stony meteorites have been measured to be roughly equal to:

the oldest ages we have measured for any bodies in the solar system

crust

the outer layer of a terrestrial planet

chromosphere

the part of the solar atmosphere that lies immediately above the photospheric layers Visible during total solar eclipse - if you look carefully Made up of hot gases - about 10,000 degrees K

differential rotation

the phenomenon that occurs when different parts of a rotating object rotate at different rates at different latitudes

Which of the following pieces of observational evidence does our modern "solar nebula" theory of the formation of the solar system NOT explain directly?

the planet of the orbit of Pluto

One reason that we have such a complex system of belts/zones/storms in Jupiter's atmosphere is that:

the planet rotates very rapidly

runaway green house effect

the process by which the greenhouse effect, rather than remaining stable or being lessened through intervention, continues to grow at an increasing rate

synchrotron radiation

the radiation emitted by charged particles being accelerated in magnetic fields and moving at speeds near that of light

magnetosphere

the region around a planet in which its intrinsic magnetic field dominates the interplanetary field carried by the solar wind; hence, the region within which charged particles can be trapped by the planetary magnetic field

transition region

the region in the Sun's atmosphere where the temperature rises very rapidly from the relatively low temperatures that characterize the chromosphere to the high temperatures of the corona

photosphere

the region of the solar (or stellar) atmosphere from which continuous radiation escapes into space Temperature is about 5800 Kelvin -sunspots here

Jupiter's upper atmosphere exhibits an intricate pattern of red and white bands around its circumference.

White bands are rising (warm) gas while red bands are sinking (cool) gas.

Discovery Stories - Uranus

William Hershel - Amateur Astronomer • March 13, 1781 • Named it Georgium Sidus • Renamed Uranus (father of Cronos - Saturn)

Is mars bigger than the Moon?

Yes, mars is quite a bit bigger than the moon

plage

a bright region of the solar surface observed in the light of some spectral line

Ganymede, the largest moon of Jupiter's, shows almost no craters, indicating that its surface must be extremely young everywhere. (true/false)

false

It's extremely rare to find asteroids outside the asteroid belt; more than 99% of all known asteroids are in the belt. (true/false)

false

Overall, conditions on the surface of Mars and Venus are remarkably similar to conditions on the surface of the Earth. (true/false)

false

The air pressure at the surface of Saturn's moon Titan is greater than on any other moon we know, but it is still MUCH less than the air pressure at the surface of the Earth. (true/false)

false

The clouds in Venus' atmosphere are made up of the same molecules as the clouds on Earth; they are just much thicker in extent. (true/false)

false

The ion tail of a comet always points directly toward the Sun; it kind of looks like an arrow without a head, aimed at the Sun. (true/false)

false

The only planet we know with rings around it is Saturn. (true/false)

false

The origin of our solar system happened so long ago that we have no evidence about how it occurred. Nothing is left from that early time. (true/false)

false

The planets, from Mercury out to Neptune, are all composed of the same elements in the same proportions. So whatever makes up most of Jupiter also makes up most of Venus. (true/false)

false

The tallest volcano in the solar system is found on planet Earth. (true/false)

false

There are a lot more volcanoes erupting each year on Earth than on Io. (true/false)

false

tail

(of a comet) consisting of two parts: the dust tail is made of dust loosened by the sublimation of ice in a comet that is then pushed by photons from the Sun into a curved stream; the ion tail is a stream of ionized particles evaporated from a comet and then swept away from the Sun by the solar wind

corona

(of the Sun) the outer (hot) atmosphere of the Sun Only visible to the naked eye during a total solar eclipse -near sunspot maximum: point edges -sunspot minimum: smoother edges Temperatures of 1 to 2 million K Best photographed in X-ray or Ultraviolet light

mare

(plural: maria) Latin for "sea;" the name applied to the dark, relatively smooth features that cover 17% of the Moon's surface

pluto

- a dwarf planet - one of five (what are the other 4?) this planet's moon, Charon, is about half the diameter of Pluto -this planet and Charon, and Neptune's moon Triton, are about half ice and half rock -Clyde Tombaugh discovered this planet on February 18, 1930

Saturn

- has a density that is less than water -is mostly made up of Hydrogen and Helium -has an extensive ring system -There is a big division between the A ring and the B ring. This division is called the Cassini division -The C ring lies inside the B ring. The F ring lies outside the A ring. -Many of Saturn's moons are "shepherd moons". They travel on the inside and the outside of a ring to keep the ring together (as with the F ring) -Mimas is partly responsible for the Cassini division (not because it is a "shepherd moon" but because itg gravity helps to keep the division clear. -has a strong magnetic field, but not as strong as Jupiter's -Titan is the largest moon of Saturn and the second largest in the solar system (how does it compare to Mercury and Pluto?) -Titan is orange and has a thick atmosphere, mostly made up of nitrogen

Mars

- has a long history of inspiring the imagination of humans. Giovanni Schiaparelli reported seeing lines on the Martian surface that he called canali and were called canals in English - indicating intelligent life here. -Many spacecraft have visited this planet, and none have found intelligent life. -A meteorite that was found in Antartica is believed to be from here. -The diameter of this planet is about half that of the Earth -The rotation period of Mars is about 24 hours -The tilt of Mars' axis is about 25 degrees - has the largest volcano in the solar system - Olympus Mons - has a huge canyon that is about 4 miles deep - Valles Marineris -Water once flowed on Mars -The main component of the atmosphere of Mars is Carbon Dioxide -The martian rocks and soil are orang-y because the iron in them has oxidized (rusted) -has two moons - Phobos and Deimos. You should know what their origin is (probably captured asteroids).

Uranus

- is sort of a light blue -is tipped so that its axis is almost in the plane of its rotation around the sun -The main components of the atmosphere of Uranus are hydrogen, helium, and methane Most of this planet's moons are named after people in Shakespearean plays -has a faint ring system -was the first planet discovered in modern times. Who discovered it, and when?

retrograde

- moon orbits in the opposite direction to the way the planet is spinning

Which of the following is evidence for volcanic activity on Venus?

- the fact that the lava plains are only 500 million or so years old - the existence of large volcanic mountains such as Sif Mons - the discovery of thousands of small volcanic cones of the surface of Venus - the pancake domes of Venus

Crab Nebula

-"star death" -where several stars are dying

Orion Nebula

-"stellar nursery" -where several stars are being born

meteors, etc.

-A meteoroid is like a tiny asteroid in space - a little piece of material like dust or rocks -A meteor is a meteoroid as it flies through the earth's atmosphere (also known as a shooting star) -A meteorite is a meteoroid that hits the ground -Most don't hit the ground - they burn up entirely in the atmosphere -Meteor showers are associated with Comets - they happen when the earth passes through some dust that blew off the comet in space -Meteorites are classified as stones, stony-irons, and irons -A few meteorites are believed to be pieces of Mars or the Moon

Asteroids

-Most (75%+) orbit the sun in the asteroid belt, which is between Mars and Jupiter -Trojan asteroids orbit the sun at the same distance as Jupiter -The largest one of these is named Ceres (it is also a dwarf planet) - believed to be planetesimals that simply did not come together to form a planet

Jupiter

-has a huge storm called the Great Red -is mostly made up of Hydrogen and Helium -rotates faster at the equator than at its poles -has 4 large moons, and many other moons (how many? check your notes) -The large moons are called the Galilean Moons because Galileo was the first to see them -The Galilean moons are Io, Europa, Ganymede, and Callisto -Ganymede is the largest moon in the solar system (how does it compare to Mercury and Pluto?) Io has many active volcanoes -Europa (also maybe Ganymede and Callisto) may have water underneath its surface (and possibly life?) -Callisto has a huge impact basin called Valhalla. -has a faint ring system - has a very strong magnetic field

Venus facts

-is completely covered in clouds. The clouds are mostly of sulfuric acid -The atmosphere on Venus is very thick - it weighs about 90 ATM (90 times thicker than the earth's.) -the atmosphere on Venus is mostly made up of Carbon Dioxide (except for the clouds, of course) -Most of the spacecraft that have gone to Venus, and the first one to land on Venus, were launched by the Soviet Union -the hottest planet in the solar system -is so hot because of the greenhouse effect (you should know how the greenhouse effect works) - is mostly covered with gently rolling hills, but it does have two continents (named Ishtar Terra and Aphrodite Terra) -The highest mountain on Venus is Maxwell Montes. -Astronomers believe there are active volcanos here -has no magnetic field -has no moon - has retrograde rotation (you should know what that means)

Magnetic field of earth

-large and helpful

how to find asteroids

-look for a moving star -the asteroid that covers the most distance is faster and therefore closer to the sun (Kepler's 3rd law) -longer streak= moving faster and closer to the sun

roche limit

-outside the roche limit the body is spherical -tidal forces start to deform the body -the body disintegrates and a ring is formed as particles orbit at different times

comets

-seem to come from the Kuiper belt, a region that extends from about the orbit of Neptune out to about 50 AU -Some theories hold that Pluto, Charon, and Triton may have originated as Kuiper belt objects -Others are thought to come from the Oort cloud, which is a spherical cloud of comet nuclei that extends out to about 50000 AU -do not develop their tail until they get about 20 AU from the sun -tails always point away from the sun -are thought to be made up of mostly ice, with some dust mixed in (like a dirty snowball) -Most have two tails - an ion (or gas) tail that goes straight away from the sun, and a dust tail that curves slightly -Halley's comet has a period of 76 years

Mercury facts

-the closest planet to the sun -looks a lot like the earth's moon- - has a small magnetic field (about 1% of the earth's) - probably has an iron core -has no permanent atmosphere -has no moon

The reason that Olympus Mons, the tallest mountain on Mars, is taller than Mount Everest (the tallest mountain on Earth) is that:

-there are no continental plates that move sideways on Mars, while there are such sliding motions on Earth -the gravity on Mars is less, so a larger mass can support itself against its own weight

Magnetic field of mercury

-very small and weak

How long does Venus take to orbit the Sun?

225 days

How long does Venus take to spin once on its axis?

243 days

global temperature rise

Average Earth Temperature 20th Century 13.9°C or 57°F Average Earth Temperature 2021 14.7°C or 58.5°F

Samples of the Moon returned to Earth as a result of the _____________ mission, show that the Moon has a much lower content of water and other _____________ materials. More recently, during the _____________ mission, NASA crashed a small spacecraft into a crater near the Moon's _____________. A plume of water and other materials was blasted outward and could be measured. Astronomers estimate that hundreds of billions of tons of frozen water can be found on the Moon, brought there by _____________ and shielded from sunlight in _____________.

Apollo, volatile, LCROSS, south pole, comets, deep craters.

Uranus and Neptune's rings

Are inside their Roche Limit So they are likely to be comets Or asteroids that got too close To the planet and are being Torn apart

Venus: hot spots Earth: both Mars: hot spots

Based on the pictures and your answers above, where do volcanoes seem to form on each of these planets?

Earth and Mars

Based on your answers above, which of these three planets seem to have plate tectonics?

Why is ultraviolet light NOT and important energy source for heating the surface of the Earth?

Because the atmosphere absorbs the majority of UV light

formation of rings

Breakup due to something (moon? Comet? Asteroid?) getting too close to the planet, inside the Roche limit • Particles from a moon • Outgassing of some sort, like with Enceladus • Dust ejected from a moon after being hit by a meteoroid • All of the giant planets have rings! So it could have been any of them....

The largest impact basin on Mercury (located on that part of the planet which is closest to the Sun at noon) is called:

Caloris

Between the A and B rings in Saturn's ring system is a big gap. First seen in 1675, this gap was named after the first person to see it.

Cassini Division

The first asteroid to be discovered (which is also the largest one) is called

Ceres

When the Dawn spacecraft explored the largest asteroid Ceres, it discovered white spots that appear to be salt and volcanic mountains made of water ice. This led astronomers to which of the following ideas:

Ceres may have (or may have had) a liquid ocean under its crust

short period comets

Come back again, with periods less than 200 years • Halley's Comet is an example • Short period comets come from the Kuiper Belt...

infrared

Comparing the ultra violet and the infrared typed of light, which has an easier time getting through the atmosphere?

ultraviolet

Comparing the ultraviolet and the infrared types of light, which experiences more absorption?

infrared

Comparing the visible and infrared types of light, which experiences more absorption?

visible

Comparing the visible and infrared types of light. which has an easier time getting through the atmosphere?

What part of the sun are you looking at if you have an X-ray filter on your telescope, so you can see X-rays coming from the sun?

Corona

Interior of Earth

Crust - rocky Mantle - rocky Outer core- liquid, iron, nickel inner core - solid iron

Where has frozen water been discovered on the Moon?

Deep inside craters in the regions near the Moon's poles

The satellite whose surface is characterized by a smooth icy crust with a complex network of cracks is:

Europa

Saturn doesn't have seasons, because its axis of rotation is not tilted significantly. (true/false)

False

The clouds we see in the atmosphere of Uranus are made of sulfuric acid. (true/false)

False

The four large moons of Jupiter were first discovered by:

Galileo with his early telescope

In the following list of some of the most interesting moons of the giant planets, please put them in order of size (diameter), starting with the largest.

Ganymede, Titan, Callisto, Io, Europa, Triton, Enceladus

discovery stories - Jupiter

Great Red Spot First seen in ? 1664? 1831 for sure -Galileo sketches in 1610

formation of the solar system

Happened about 4.5 Billion years ago Formation took 200 - 500 Million years to complete • Cloud of gas and dust starts to collapse • Solar Nebula forms • Protosun at the center • Cloud heats up, spins faster, flattens out • Planetesimals form from condensation • Protoplanets form from planetesimals • Planets form from protoplanets

What makes astronomers believe that Mars once had rivers and running water?

Images from orbiting spacecraft reveal ancient channels that look like dried-up river beds on Earth (and our rovers show geological formations made by running water)

Why are there no smaller craters on the surface of Venus, only bigger ones?

In Venus' thick atmosphere all smaller chunks of material burn up before they can reach the surface

Based on the solar nebula model, why wouldn't we expect a terrestrial planet to form in the outer solar system?

In the outer solar system, anything that was massive enough to form a terrestrial planet-sized object would likely have succeeded in also drawing a lot of ices and H and He to itself, producing a gas giant.

The world in the solar system that is most active volcanically is:

Io

One of the following worlds has an orbit that actually crosses the orbit of another world. This "rude" world is:

Pluto (and the orbit it crosses it Neptune's)

solar flares

Powerful bursts of energy, that leave The sun as light (or x-rays) Associated with the magnetic field They tend to form over sunspots They last from minutes to hours

jupiter's rings

Probably formed from dust from small moons hit by meteoroids

Which planets formed at temperatures hotter than the boiling point of water?

Rocky terrestrial planets

Many worlds in the solar system show extensive impact cratering, dating back billions of years. Which of the following worlds does NOT show such cratering?

Saturn (cuz its a gas giant)

Discovery stories - Saturn

Sketched by - Galileo 1610 - 1623 - Huygens 1610-1646 - Hooke 1666 -Cassini 1676

SOHO

Solar and heliospheric observatory EIT is the instrument on the SOHO satellite that took the picture The number is the wavelength in Angstroms Angstroms - one ten-billionth of a meter

Greenhouse effect

Some wavelengths of light are absorbed more than others. This diagram shows the primary gas molecules responsible for absorbing the different wavelengths of light

The total surface area of planet Mars is roughly equal to the

Surface area of the Earth's continents

How doe the mass of the Sun compare to that of Jupiter?

The Sun about 1000 times more mass than Jupiter

The earth and the inner planets dont have much hydrogen in their atmospheres and yet the sun is 75% hydrogen, why?

The escape velocity of the sun is much higher, so the hydrogen couldn't leave

Why does Mars have an overall reddish color when we see its surface from afar?

The material of Mars' surface contains a lot of iron oxide, the same chemistry that makes rusting metals look reddish

Which of the following statements about Saturn's rings is TRUE?

The rings are made of billions and billions of individual "moonlets" (small chunks)

Astronomers have discovered gas giant planets like Jupiter orbiting companion stars at closer than 0.7 AU (about the distance of Venus's orbit). Why don't astronomers believe that these gas giant planets originally formed at these locations?

The temperature in the early solar nebula was too high at these distances.

seismic waves

These are waves that spread through the interior of Earth from earthquakes or explosion sites. -how scientists are able to gauge what the interior layers of planets are (solid or liquid)

How can astronomers measure the age of a meteorite that fell from the skies?

They measure the amount still left of radioactive materials in the meteorite, and how much has turned into decay products

only one moon in the solar system with a substantial atmosphere?

Titan

The atmosphere of Venus is mostly carbon dioxide, and the atmosphere of the Earth has water vapor. Why are these two gases absent in the atmosphere of the satellite around Saturn called Titan?

Titan is so cold that carbon dioxide and water vapor freeze out

Most famous retrograde moon

Triton of neptune

Neptune

Voyager 2 - 1989 -a dark blue color -When Voyager II flew by this planet it had a big storm called the Great Dark Spot -The main components of the atmosphere of this planet are hydrogen, helium, and methane -has a faint ring system -probably captured most of its moons -Triton is this planet's largest moon, and is very similar to Pluto and Charon (how does it compare in diameter?) -Triton goes around this planet in a retrograde fashion -Triton is believed to have nitrogen geysers on its surface -has an interesting discovery story. Who discovered it, and when?

Ultraviolet: O2 or O3 visible light: none Infrared: H20

What gas molecules are primarily responsible for the absorption of each of the following types of light in our atmosphere?

stony meteorite

a meteorite composed mostly of stony material, either primitive or differentiated

iron meteorite

a meteorite composed primarily of iron and nickel

Maunder minimum

a period during the seventeenth century when the number of sunspots seen throughout the solar cycle was unusually low

exoplanet

a planet orbiting a star other than our Sun

meteorite

a portion of a meteor that survives passage through an atmosphere and strikes the ground -actually lands on the ground • Falls - meteorites people saw fall Finds - meteorites that people found -most meteorites are stony and come from broken off bits of type S asteroids

coronal hole

a region in the Sun's outer atmosphere that appears darker because there is less hot gas there

kuiper belt

a region of space beyond Neptune that is dynamically stable (like the asteroid belt); the source region for most short-period comets • It is a region from about 30 AU to 50 AU • Mostly icy bodies - like Pluto, its moon Charon, probably Triton came from there

comet

a small body of icy and dusty matter that revolves about the Sun; when a comet comes near the Sun, some of its material vaporizes, forming a large head of tenuous gas and often a tail -often blamed for disaster's in history -Tycho Brahe proved in 1577 that they were something in space - not part of the atmosphere -an orbiting celestial body made up of ice, gases, rock, dust, and organic compounds - basically like a "dirty snowball" -nucleus, coma, and tail (components)

meteor

a small piece of solid matter that enters Earth's atmosphere and burns up, popularly called a shooting star because it is seen as a small flash of light -moving through the atmosphere -"shooting star" - The friction as it falls through air Produces heat and light

The typical meteor is

a small solid particle, no bigger than a pea

coronal mass ejection (CME)

a solar flare in which immense quantities of coronal material—mainly protons and electrons—is ejected at high speeds (500-1000 kilometers per second) into interplanetary space -A bubble of gas in the corona bursts and sends a charged particle gas out into the solar system

At their centers, all the jovian planets have cores made of:

a solid mixture of rocky and icy materials under great pressure

asteroid

a stony or metallic object orbiting the Sun that is smaller than a planet but that shows no evidence of an atmosphere or of other types of activity associated with comets • Basically big rocks in space. • Most orbit in the Asteroid Belt, between Mars and Jupiter, at around 3 AU -very far apart actually -bigger than a meter

solar flare

a sudden and temporary outburst of electromagnetic radiation from an extended region of the Sun's surface

stony-iron meteorite

a type of differentiated meteorite that is a blend of nickel-iron and silicate materials

granite

a type of igneous silicate rock that makes up most of Earth's continental crust

will the infrared given off by the earth's surface easily travel back through the atmosphere to space or get absorbed?

absorbed by atmosphere

If there are at least a million asteroids, how did spacecraft like Galileo survive their trip through the asteroid belt?

although there are many asteroids, they are widely spaced (there is lots of space between them)

near-Earth asteroid (NEA)

an Earth-approaching asteroid, one whose orbit could bring it on a collision course with our planet

active region

an area on the Sun where magnetic fields are concentrated; sunspots, prominences, flares, and CMEs all tend to occur in active regions

resonance

an orbital condition in which one object is subject to periodic gravitational perturbations by another, most commonly arising when two objects orbiting a third have periods of revolution that are simple multiples or fractions of each other

We believe the maria on the Earth's Moon are:

ancient impact craters in which lava beds welled up from inside the Moon

giant planet

any of the planets Jupiter, Saturn, Uranus, and Neptune in our solar system, or planets of roughly that mass and composition in other planetary systems

terrestrial planets

any of the planets Mercury, Venus, Earth, or Mars; sometimes the Moon is included in the list -smol n' rocky -impact craters

sunspots

are cooler - about 4000- 4500 Kelvin, and so they are not as bright -associated with the magnetic field of the sun

Why were asteroids not discovered until the 19th century?

asteroids are generally small compared to planets and require a good telescope and patient searching to spot them

Which of the following is NOT a way that the moon Titan resembles the Earth?

at its surface the temperature and pressure are just right for water to exist in all three phases (gas, liquid, and ice)

Why are the largest craters we find on the Moon and Mercury so much larger than the largest craters we find on the Earth?

because the largest craters were made early in each world's history, and geologic activity has erased all traces of this early period on the Earth's surface

The rings of the outer planets consist of

billions of chunks (of various sizes) that all orbit the equator of each planet

More than 75% of the known asteroids:

can be found in a belt between Mars and Jupiter

P waves (earthquakes)

can go through liquid

S waves (earthquakes)

can not go through liquid

Our two neighbor planets have similarities, but also many differences. One similarity is that both their atmospheres have _______ as the main gas. But because of its lower ________, Mars has lost much of its early atmosphere, while Venus has not. From orbit, Mars's air is pretty transparent, except when there are global __________. The air on Venus is never transparent; all we can see are the tops of the ________. One kind of geological feature that both planets have are __________.

carbon dioxide, gravity, dust storms, clouds, volcanoes

In the infrared portion of this diagram, the dips indicate what?

certain infrared wavelengths that are absorbed less by greenhouse gases and pass through the atmosphere

photochemistry

chemical changes caused by electromagnetic radiation

The fact that some asteroids cluster in what are called asteroid families is probably the result of:

collisions which broke up larger bodies into a number of smaller ones

Short-period comets like Comet Halley

come back again and again at predictable intervals

Interior of Venus

crust -liquid outer core -solid inner core?

will the visible light reflected by the earth's surface easily travel back through the atmosphere to space or get absorbed?

easily travel back to space

All the objects designated as dwarf planets lie in the Kuiper Belt. (true/false)

false

Among the inner (terrestrial) worlds, the smaller the world, the greater the geologic activity we find in it. (true/false)

false

Because it has a thick atmosphere, Saturn's moon Titan can have weather. The clouds and rain on Titan are made of water droplets, just like the clouds and rain on Earth. (true/false)

false

The primary clouds in the atmospheres of Jupiter and Saturn are composed of:

frozen ammonia crystals

tectonic

geological features that result from stresses and pressures in the crust of a planet; tectonic forces can lead to earthquakes and motion of the crust

Our solar system is believed to have formed following the collapse of a

giant gas cloud

Which theory of the Moon's origin do astronomers (and the evidence) favor:

giant impact theory

differentiation

gravitational separation of materials of different density into layers in the interior of a planet or moon

velocity of gases is determined by temperature and mass

higher temp - higher speed higher mass - lower speed

By far the most abundant element in the giant (jovian) planets is:

hydrogen

The element that can act like a metal when it is under tremendous pressure and is probably responsible for Jupiter and Saturn's magnetism is:

hydrogen

basalt

igneous rock produced by the cooling of lava; makes up most of Earth's oceanic crust and is found on other planets that have experienced extensive volcanic activity -lava that is enriched in iron and magnesium and low in silica will cool and form this

What features are abundant on Callisto and Ganymede and almost absent on Europa and Io?

impact craters

fault

in geology, a crack or break in the crust of a planet along which slippage or movement can take place, accompanied by seismic activity

dwarf planets

in orbit around the sun has enough mass to be round has not really cleared the neighborhood around its orbit 5 officially recognized ones Pluto - orbit 39 AU -largest Eris - orbit 68 AU - largest, outer solar system Haumea - 43 AU - outer solar system Makemake - 45 AU - outer solar system Ceres - 2.8 AU - in asteroid belt, smallest

minor planets

in orbit around the sun, not a planet, not a comet, not a moon (asteroids) -smaller than dwarf planets

Where is your telescope located to see the x-rays coming from the sun?

in space, because the earth doesn't allow x-rays to pass through the atmosphere

Some of the early planetesimals that formed the solar system still survive today. Where would you find such planetesimals?

in the asteroid and Kuiper belts

Which of the following statements about the planet Venus is true?

it has a thick layer of clouds containing sulfuric acid droplets

Valles Marineris is a wide, deep network of chasms stretching for some 2500 miles on the surface of Mars. How do we believe such a big set of canyons formed originally?

it was caused by tectonic pressures from deep within the planet

The sun probably has a liquid core. What is it about the sun that makes us think that?

its magnetic field

Which of the following is a way that the planet Mercury is similar to the Moon?

its surface is heavily cratered

Which planets formed at temperatures cooler than the freezing point of water?

jovian gas giant planets

The giant planet that has an axis that points roughly straight up, and thus has no seasons to speak of, is:

jupiter

planetesimals

objects, from tens to hundreds of kilometers in diameter, that formed in the solar nebula as an intermediate step between tiny grains and the larger planetary objects we see today; the comets and some asteroids may be leftover planetesimals

A crucial difference that helps explain why Venus is so hot and the Earth isn't is that:

on Venus, there was eventually no ocean to remove carbon dioxide from the atmosphere

Suppose you observed a comet with an orbit that had a high inclination, tilted 75 degrees above the plane of the solar system.

oort cloud

The large reservoir of comet nuclei far beyond Pluto, from which we believe new long-period comets come into the inner solar system, is called:

oort cloud

pluto

orbit is tipped and sometimes closer to the sun than neptune -water ice crust -possible liquid ocean under the ice -silicate core -big moon charon

When the solar system was forming, the building blocks from which the protoplanets gathered together were the:

planetesimals (a few km to tens of km wide)

One region on Earth that has become a rich source of new meteorites in recent decades (including the meteorite from Mars that got famous because some scientists claimed they had found evidence for the building blocks of life on Mars) is:

the Antarctic

In its overall composition, the Moon roughly resembles:

the Earth's crust and mantle

Our modern understanding of Pluto is that it is a member of

the Kuiper Belt (of trans-Neptunian objects)

Which of the following does the composition of a planet like Jupiter resemble:

the Sun

greenhouse effect

the blanketing (absorption) of infrared radiation near the surface of a planet—for example, by CO2 in its atmosphere

core

the central part of the planet; consists of higher density material

The reason that worlds like the Earth are differentiated is that

the continuing impacts on a growing protoplanet eventually melted the entire body

accretion

the gradual accumulation of mass, as by a planet forming from colliding particles in the solar nebula

What is the cause of its many volcanic/geyser-like eruptions on the moon Io?

the gravitational stress of being so close to Jupiter and its other large moons heats Io's inside

tidal heating

the heating of a planet or moon's interior by variable tidal forces caused by changing gravitational pull from a nearby planet or moon

According to the giant impact hypothesis about the formation of the Moon, why did the Earth not break apart into many pieces when the giant impact happened?

the impactor was about the size of Mars or smaller, so it ejected material from the Earth but did not break it

Oort cloud

the large spherical region around the Sun from which most "new" comets come; a reservoir of objects with aphelia at about 50,000 AU

A key difference between the protoplanets that formed in the outer solar system and those that formed in the inner solar system was that

those in the outer solar system were in a place where ice, not just rock, condensed and thus could grow larger

Among solid worlds, which type of world is most likely to have significant geological activity?

those that are the largest (and retain heat the best)

half-life

time required for half of the radioactive atoms in a sample to disintegrate

All the giant planets in our solar system are surrounded by a family of moons (true/false)

true

All the planets in the solar system orbit the Sun in the same direction. (true/false)

true

Among Pluto's moons, there is one big one called Charon, which is roughly half of Pluto's diameter. (true/false)

true

Astronomers now believe that under the surface ice of Europa there is a layer of more liquid material, perhaps even a global underground ocean. (true/false)

true

Edmund Halley didn't discover the comet named after him; instead, he was the first to show that the comet's orbit brought it back to the inner solar system every 76 years or so. (true/false)

true

In 1992, astronomers discovered the first small member of the Kuiper belt. Since then, more than a thousand smaller members of that belt have been discovered. (true/false)

true

Jupiter has more mass than all the other planets combined. (true/false)

true

Jupiter is the largest planet in our solar system. (true/false)

true

Jupiter's moon Europa has a very young surface, with few craters. It has many cracks in the ice and other features showing that it has an active surface. (true/false)

true

M-type or metallic asteroids are relatively rare; dark C-type or carbonaceous asteroids are more common. (true/false)

true

Mercury and the Moon were too small, and thus had too little gravity, to hold on to a substantial atmosphere. (true/false)

true

More than 200 moons have been discovered so far in the solar system, most of them around the four giant planets. (true/false)

true

Once the inner planets formed, their surfaces early on were bombarded with left-over planetesimals and even a few mini-planets (or proto-planets) that were moving about. (true/false)

true

One place where astronomers can get photos of asteroids up close is around Mars; Mars' two small moons are just captured asteroids. (true/false)

true

Saturn's moon Titan has rivers and lakes, just as Earth does, but they are not made of water. (true/false)

true

Saturn's rings are much wider than they are thick. (true/false)

true

Several lines of evidence show that the solar system must have formed about four a a half billion years ago from a cloud of gas and dust we call the solar nebula. (true/false)

true

What two types of light account for the majority of the energy coming from the sun?

visible and infrared

Due to the light absorbed by Earth's surface that was emitted by the atmosphere, is Earth's temperature near the surface warmer or cooler than it would have been without this light?

warmer

A student in your class whom you kind-of like asks you come to watch a meteor shower. What exactly are you being invited to?

watching the left-over dirt from a comet burn up by friction as the pieces hit the Earth's atmosphere

Saturn's ring particles are composed mainly of:

water ice

shield volcano

what type of volcano is this?

stratovolcano

what type of volcano is this?

A ring particles

which particles will move the slowest?

does jupiter have a magnetic field?

yes

Do you think the earth's surface gives off any light at night?

yes, infrared

Does the earth give off light at night?

yes, infrared light

Which of the jovian planets does NOT have any satellites?

you can't fool me, all the jovian planets are accompanied by satellites

composition of the sun

• 73% hydrogen 25% helium

composition of Saturn

• 75% hydrogen • 25% helium

composition of Jupiter

• 90% hydrogen 10% helium

Bode's law

• A pattern detected in the orbits of the planets: -take a number and double it, add 4, and then divide by 10 to find the approximate distance from the sun in AU -does not work once it reaches neptune

where do moons come from

• Capture by the planet of a passing asteroid or other body (like Triton). All retrograde moons are assumed to have been captured • Formation in place, at about the same time as the planet was forming • Collisions of planet sized objects (like the formation of Earth's moon)

Long period comets - Oort cloud

• Come from a theorized place known as the Oort Cloud • Spherical in shape • 2000 to 100,000 AU from sun • May contain a trillion objects

What causes a planet's magnetic field?

• Dynamo Theory • Requires fast spinning • Requires conductive fluid • Requires convection

greenhouse effects on the planets

• Earth • Temperature without greenhouse effect: -18°C (about 0°F) • Temp. with greenhouse effect: 13.9°C (about 57° F) (20th century avg) • Venus • Without greenhouse effect: -41°C • With greenhouse effect: 462°C • Mars • Without greenhouse effect: -64°C • With greenhouse effect: -58°C

How Mars created a new atmosphere

• For a while, Mars was warm enough for liquid water (there is evidence of water) • Some CO2 was absorbed in the water à carbonate rocks? Not as much • Eventually, Mars cooled enough that the water froze out (and left the atmosphere). • Leaving primarily CO2 in the atmosphere • The solar wind has blown away a lot of the atmosphere • After the planet cooled and its magnetic field stopped, nothing protected it

discovery of asteroids

• Giuseppe Piazzi, Jan. 1801 - Ceres • Pallas 1802, Juno 1804, Vesta 1807 -current known asteroid count: 1,113,527

Discovery Stories - Neptune

• John Couch Adams • Sept. 1845 - finished calculations, contacted director of Cambridge Observatory? • Urbain Le Verrier • Nov. 1845 - realized there was something wrong with Uranus's orbit • Finished calculations in June 1846 • British astronomers started looking for the planet in July 1946, saw it in August and didn't realize it • French astronomers were not interested in looking • Finally a German astronomer was sent Le Verrier's calculations, and found the planet that same night.

where are asteroids found

• Most are in the asteroid belt • Trojan asteroids are found in Jupiter's orbit

How Venus created a new atmosphere

• Never cool enough for liquid water! • So CO2 remains in the atmosphere. • But where did the H2O go? • One hypothesis has it being split (by UV light) into both hydrogen and oxygen, which both leave the atmosphere

the sun

• Our closest star! • is a balance of gravity pulling in and heat pushing it out • Two main parts - interior and exterior. • About 73% hydrogen • About 25% helium • About 2% other things - iron, calcium, oxygen, nitrogen, etc.

how does an atmosphere absorb EM radiation?

• The energy is absorbed by molecules in the atmosphere. • Sometimes it makes these molecules break apart (they have too much vibrational kinetic energy and just pop apart) -Absorbing any kind of electromagnetic radiation ("light") warms the gasses in the atmosphere -Many planets do not have a stratosphere because they don't have ozone to absorb UV light

what are asteroids made of?

• Type C - carbonaceous (silicate rocks + carbon compounds) • Type S - Stony (silicate rocks) • Type M - Metalic (iron & nickel)

How Earth created a new atmosphere

• Warm enough so that H2O can be liquid à oceans! • CO2 dissolved in the oceans (creating limestone, etc.) • So a lot of the carbon dioxide (CO2) left the atmosphere • Life! • Oxygen reacts with many things - the only way to have oxygen in the atmosphere is to keep replenishing it. Plants take in CO2 and give off oxygen.

escape velocity

• Where M is the mass of the planet and r is the radius of the planet • This applies to gases in the atmosphere, too -the minimum speed needed for a free, non-propelled object to escape from the gravitational influence of a primary body

The second atmosphere

• Where does it come from? Volcanoes! • H2O 58% • CO2 23% • SO2 13% • N2 5% • Others 1%

The first atmospheres

• Would have formed from the stuff in the cloud of gas and dust that formed all the planets • So it would have been mostly Hydrogen and Helium (H and He) • What happened to it? = escape velocity