Jovian Planets Magazine Front page layout by: Carlos De la Cruz and Salvador Winn

Editor: Andrew Grenbemer

Table of Contents

Overview of Jovian Planets Page 1

Overview of Jupiter Page 2

Overview of Saturn Page 3

Overview of Neptune Page 4

Overview of Uranus Page 5

Pluto Page 6

Discovery of Jupiter Page 7

Discovery of Neptune and Uranus Page 8

Discovery of Pluto Page 9

Surfaces of the Jovian Planets Page 10

Weather on the Jovian Planets Page 11

Recent Images of the Jovian Planets Page 12

Galilean Moons of Jupiter Page 13

Moons of Jovian Planets Page 14

Planetary Rings Page 15

Rings of Saturn Page 16

Gas Giants vs Ice Giants Page 17

Maelyn Leis

Unlike how it sounds, ice giants aren’t necessarily made up of ice--they’re

just comprised of substances heavier than

hydrogen and helium, and though those

substances might have been ice at the planet’s

formation, they now exist in a variety of

stages (solid, liquid, and gas).

Uranus and Neptune are the only ice giants in the solar system. Uranus

has more hydrogen and helium, but is less

massive than Neptune, while Neptune is very

dense and has a hot core and active

atmosphere.

Both gas and ice giants are different from

terrestrial planets, which are rocky.

Jupiter and Saturn are gas giants. Uranus and

Neptune are also sometimes considered gas

giants, but they were redefined as ice giants

to show the difference in their structure.

Jupiter and Saturn are much larger planets, as

well. Gas giants aren’t made of solid material; instead, their atmospheres are a

thick gas comprised of hydrogen and helium.

The planet’s gases gradually thin to nothing

the farther from the planet.

The term “gas giant” was actually coined by a science fiction writer and

isn’t a totally accurate name, since the planets

are made up of liquid and gas, and because of

the temperature, the two are hardly

distinguishable.

While gas giants have metallic hydrogen

cores, ice giants do not. The hydrogen cores

are “metallic” because the pressure makes the hydrogen a conductor.

Neptune

Uranus

Mars is a terrestrial planet

Becca Bright

Information Source: http://en.wikipedia.org/wiki/Main_Page

The Jovian Moons

The Jovian planets are best known for being not only the largest planets in our Solar

System, but also known for being the planets with the most moons. Being either large

or small, volcanic or frozen, there is much more to these moons than meets the eye.

There are 67 confirmed Jovian moons, 53 officially named Saturnian moons (9 more

have confirmed orbits, but have not yet been officially named, otherwise the total

would be 62), 27 known Uranian moons, while there are 14 known Neptunian moons.

Io: The driest known object in our Solar System, Io (a moon of Ju-

piter) is named after a priestess of Hera in Greek mythology, who

was also one of Zeus/Jupiter’s lovers. Nicknamed the “cosmic piz-

za,” Io is the most geologically active body in our Solar System with

over 400 active volcanoes. Io is also possibly the most colorful ob-

ject in our Solar System, painted by the volcanic plumes and lava

flows, coloring the surface subtle shades of yellow, red, white,

black, and green.

Europa: Icy and small, Europa is named after the mortal Eu-

ropa, a Phoenician woman of high lineage in Greek mytholo-

gy, and one of Zeus/Jupiter’s lovers. A water ocean is

thought to exist beneath the thick ice of Europa, which

could serve as a home for extraterrestrial life. In fact, as of

September 2014, NASA reported finding evidence confirm-

ing earlier reports of plate tectonics in the thick casing of

ice, the first sign of such geological activity on another world

other than Earth. A mission to Europa is planned to launch

in 2022.

Ganymede: The largest moon both of Jupiter and our Solar System,

Ganymede is named after the cupbearer of the gods in Greek my-

thology, and is one of Zeus/Jupiter’s many lovers. Ganymede is

also the only moon known to possess a magnetosphere. Its diame-

ter is 2% larger than that of Titan, the second largest moon in the

Solar System.

Callisto: If Callisto were closer, it could be mistaken for our

own moon! Callisto is named after a nymph from Greek

mythology, and a lover of Zeus/Jupiter. Callisto looks very

similar to our moon, and is tidally locked to its revolution

around Jupiter. The surface is possibly the oldest and most

heavily cratered in our Solar System. The presence of an

ocean within Callisto leaves the possibility that it could

harbor life, though the conditions are thought to be less

favorable than on nearby Europa.

Becca Bright

Information Source: http://en.wikipedia.org/wiki/Main_Page

Titan: The largest moon of Saturn and the second largest moon

in the Solar System. Titan is named after the powerful deities of

Greek mythology known as Titans. Titan is also the only known

natural satellite to have a dense atmosphere and have clear evi-

dence of stable bodies of surface liquid. The climate (which in-

cludes wind and rain) creates surface features similar to those of

Earth’s. Dunes, rivers, lakes, seas, and deltas can form from Ti-

tan’s wind and rain. On June 23, 2014, NASA found strong evi-

dence that the nitrogen in Titan’s atmosphere came from materi-

als in the Oort cloud, which is associated with comets, and not

from the materials that formed Saturn.

Enceladus: A very bright Saturnian moon, named after the

giant Enceladus of Greek mythology. Though it may be small

(only 500 km in diameter), it reflects almost all the sunlight

that strikes it, making it one of Saturn’s brightest moons. En-

celadus orbits in the densest part of Saturn’s diffuse E-ring.

The surface consists of a wide range of features, from old and

heavily cratered, to young and tectonically deformed terrain.

The discovery of cryovolcanoes (ice volcano, volcanoes that

erupt volatiles such as water, ammonia, or methane instead of

molten rock) on its surface revealed that Enceladus has re-

leased most of the materials that make up Saturn’s E-ring.

Tethys: Named after an aquatic sea goddess of Greek mythology.

Tethys is heavily cratered and vary bright, the second brightest

moon of Saturn after Enceladus. Though the least dense of all

the major moons in the Solar System, Tethys is full of unique sur-

face features. The most prominent feature on Tethys is an im-

pact crater-Odysseus-which is about 200 km in diameter.

Miranda: An extreme terrain gives Miranda a rough surface.

Miranda is named after a character from Shakespeare’s The

Tempest. Miranda possesses the most extreme and varied

topography, the highest cliff (Verona Rupes) being 20 km high,

the tallest in the Solar System. It is also known to be one of

the smallest objects in the Solar System to be spherical under

its own gravity. Unfortunately, the origin and evolution of its

geology is not fully understood.

Umbriel: Not much is known about Umbriel, a Uranian moon

named after the character from Alexander Pope’s The Rape of

the Lock. The surface is the darkest among the Uranian moons

and appears to be shaped primarily by impacts. However, the

presence of canyons suggests early endogenic processes, and the

moon may have undergone and early endogenically driven resur-

facing event that obliterated its outer surface. Its most promi-

nent feature is a ring of bright material on the floor of Wunda

crater.

Becca Bright

Information Source: http://en.wikipedia.org/wiki/Main_Page

Titania: Uranus’s largest moon, Titania is named after the

queen of the fairies in Shakespeare’s A Midsummer Night’s

Dream. Relatively dark and slightly red in color, Titania ap-

pears to have been shaped by both impacts and endogenic

processes. Not very much is known about Titania, but infra-

red spectroscopy conducted from 2001 to 2005 revealed the

presence of water ice as well as frozen carbon dioxide on the

surface. This suggests that the moon may possess a tenuous

carbon dioxide atmosphere.

Oberon: Uranus’s outermost major moon, Oberon is named after

the mythical king of the fairies who appears as a character in

Shakespeare's A Midsummer Night’s Dream. Among the most

heavily cratered of the outer moons, the largest impact craters

reach up to 210 km in diameter. The surface has been primarily

shaped by asteroid and comet impacts. It appears to be similar in

color to Titania’s surface.

Triton: The largest moon of Neptune, Triton is named after

the son of Poseidon/Neptune. The orbit of Triton is retro-

grade, the only large moon in the Solar System with such an

orbit. This, along with its composition (mostly frozen nitro-

gen, a mostly water ice crust, an icy mantle, and a substan-

tial core of rock and metal), has led to the hypothesis that

Triton may not have formed with Neptune, but may have

been captured from the Kuiper belt.

Thalassa: Very little is known about this second innermost satellite

of Neptune, which is named after a sea goddess from Greek my-

thology. The only things known about Thalassa is that it is irregu-

larly shaped and shows no sign of any geological modification. It is

likely that is is a rubble pile re-accreted from fragments of Nep-

tune’s original satellites, which were smashed up by perturbations

from Triton soon after that moon’s capture into a very eccentric

initial orbit. Unusually for irregular bodies, it appears to be rough-

ly disk-shaped. Since the Thalassian orbit is below Neptune’s syn-

chronous orbit radius, it is slowly spiraling inward due to tidal de-

celeration and may eventually impact Neptune’s atmosphere, or

break up into a planetary ring upon passing its Roche limit due to

tidal stretching.

Becca Bright

Information Source: http://solarsystem.nasa.gov/index.cfm

Planetary Rings

One of the most unique features of the Jovian planets lie not only in the atmospheres that seem

to dominate their visual surface, but also in their rings.

The rings of Jupi-

ter appear to be created by

dust thrown off by impacts

on small moons that orbit

within them. The outer

rings (or known as the gos-

samer rings, which are

6500 km wide) actually

outline the orbits of Amal-

thea and Thebe (two Jovian

moons). The flat main ring

is outlined by the orbits of

Adrastea and Metis (two

more Jovian moons). The

halo, or inner ring, is ap-

proximately 20000 to

40000 km in overall thick-

ness. Its shape is thought

to be due to electromag-

netic forces within Jupiter’s

magnetosphere acting on

the dust particles of the

ring.

Puzzling astrono-

mers since Galileo Galilei’s

discovery of them with his

telescope in 1610,

Saturn’s complex ring sys-

tem still has yet to be fully

understood. By far,

Saturn’s rings are the larg-

est and most spectacular.

Billions of ring particles

(made mainly of ice)

make up the entire ring

system. There are so

many rings of varying

thickness that gaps exist

between some of them,

and some large enough

for tiny moons to orbit

through. The Cassini mis-

sion (which is already or-

biting Saturn) will help us

further understand how

these magnificent rings

formed, how they main-

tain their orbit, and above

all, why they are there in

the first place.

The scientists pre-

paring to watch Uranus

pass in front of a star in

1977 were eager for this

rare chance to observe a

distant planet. But they

did not expect to find rings

surrounding the planet.

Occasionally, the star ap-

peared to blink out several

times, this was caused by

the rings blocking the star-

light. The Kuiper team

observing the planet were

able to identify 5 narrow

rings, while the Perth team

identified 6 more. Now, 15

rings have been identified

after a closer view from

the Voyager 2 spacecraft

(two of these were discov-

ered by the Hubble Space

Telescope in 2005). It is

not entirely known what

the rings are made of, but

some of the larger rings

are surrounded by belts of

fine dust.

The first evi-

dence found on Nep-

tune’s rings came from a

stellar occultation experi-

ment in the mid 1980s, an

extra “blink” was shown

just before or after the

planet occulted the star.

Images from Voyager 2 in

1989 found the planet to

be surrounded by several

faint rings. The outer-

most of these rings con-

tains three prominent

arcs. The existence of

these arcs are very diffi-

cult to understand be-

cause the laws of motion

would predict that arcs

spread out into a uniform

ring over very short time-

scales. The gravitational

effects of Galatea (a Nep-

tunian moon just inward

from the ring) are now

believed to confine the

arcs. As of today, we still

do not know of the com-

position of Neptune’s

rings.

Jupiter is the most massive planet in

our solar system, with dozens of moons

and an enormous magnetic field. Jupiter

forms a kind of miniature solar system.

People have said that Jupiter resembles a

star in composition, but did not grow big

enough to ignite. The planets swirling

cloud stripes is created by massive storms

such as the great red spot , which has

raged for hundreds of years. Jupiter also

orbits the sun and one day on Jupiter takes

Jupiter is the fifth planet from the sun at a distance of about seven hundred and seven-

ty-eight million km. Jupiter makes a complete orbit around the sun about every twelve years

which is four thousand three hundred and thirty-three earth days.

Jupiter has a gas giant planet and therefore does not have a solid surface, but it howev-

er is predicted that Jupiter has an inner solid core about the size of earth. Jupiter’s atmos-

phere is made up mostly of hydrogen and helium.

Jupiter has fifty known moons, with an additional seventeen moons awaiting confirma-

tion of their discovery that is a total of sixty-seven moons. Jupiter has a faint ring system

which was discovered in 1979 by the voyager two mission. Many missions have been made

out to Jupiter and its system of moons, Juno’s mission will arrive in 2016.

As far as we know Jupiter cannot support life, however Jupiter’s moons might be

able to support life because some of the moons provide oceans underneath their

crusts

Jupiter is a very active planet. A plethora of storms rage all over its surface, the

most famous being the 'Great Red Spot'. This is a gigantic rotating storm, wider

than 3 'Earth diameters'. It is highly complex and moves in a generally anti-

clockwise direction, and historical records of Earth-based observations show that is

has existed for at least 100 years.

Jupiter is the fourth brightest object in the solar system:

Only the Sun, Moon and Venus are brighter. It is one of five planets visible to the

naked eye from Earth.

PLUTO Pluto was discovered in 1930. Pluto

was considered our ninth planet up

until 2006. Pluto is now considered a

dwarf planet. A dwarf planet orbits the

sun just like other planets, but is

smaller. Dwarf planets are so small

that they cannot clear other objects

out of its path.

Plutos surface is icy cold. The average

temperature is 44 Kelvin, or -380

Farenheit. The surface is covered by

exotic ices such as methane and

nitrogen frost. Pluto has an estimated

diameter less than 1/5 of the earths

moon. The surface is roughly -375 degrees Farenheit. The surface looks reddish,

yellowish and grayish. When compared with past images, the Hubble pictures

show that over time Pluto has gotten redder, apparently from seasonal changes.

Pluto has five moons. One of those moons is

about half the size of Pluto. That is quite

unusual because most Planets are a lot bigger

than their moons. Pluto’s moon’s name is

Charon. Pluto and Charon are only 12,200 miles

apart. Charon’s orbit around Pluto takes 6.4

earth days. This is because Charon hovers over

the same spot on Pluto’s surface and the same

side of Charon always faces Pluto, a

phenomenon known as tidal locking.

By: Lila Kennedy

Comparison of the size of Earth to Pluto

Pluto

Pluto is the largest object in the Kuiper

belt and the second-most-massive

known dwarf planet.

Discovered in 1930, Pluto was originally

classified as the ninth planet from the

sun. Its status as a major planet fell into

question following further study of it

and outer solar system over the ensur-

ing 75 years.

Santiam Seventh Period Astronomy

Class Magazine 11/3/14

The Discovery of Pluto

By: Carlos Dela Cruz

Pluto has five known moons: Char-

on (the largest of them all). Nix, Hy-

dra, Kerberos, and Styx. Pluto and

Charon are sometimes described as

a binary system because the bary-

center of their orbits does not lie

within earlier body.

Alternate picture of Pluto.

Pluto and Charon (Plutos’ biggest moon)

Discovery of Pluto page 2

By: Carlos Dela Cruz

On July 14, 2015, the Pluto system

is due for a visit by spacecraft for

the first time. The new horiszons

probe will be passing by and taking

pictures of it. In 1978 the discovery

of plutos moon Charon allowed

the measurement of Pluto’s mass

of the first time.

Once discovered, Planet X needed a name.

Everyone had an opinion. However, the name

Pluto was chosen on March 24, 1930 after 11-

year-old Venetia Burney in Oxford, England

suggested the name "Pluto." The name de-

notes both the assumed unfavorable surface

conditions (as Pluto was the Roman god of

the underworld) and also honors Percival

Lowell, as Lowell's initials make up the first

two letters of the planet's name.

Pluto is the planet farthest from

the sun. This great distance from

the sun makes Pluto very inhospi-

table; it's surface is expected to be

made up of mostly ice and rock

and it takes Pluto 248 years just to

make one orbit around the sun.

Surfaces of the Jovian planets

A gas giant is a massive planet with a thick atmosphere of hydrogen and

helium. They may have a dense molten core of rocky elements, or the core may

have completely dissolved and dispersed throughout the planet if the planet is hot

enough. The hydrogen and helium in basic gas giants like Jupiter and Saturn

constitute most of the planet, instead they only make up an outer envelope on

Uranus and Neptune, which are sometimes called ice giants, because they are

mostly composed of water, ammonia, and methane.

Among extrasolar planets, Hot Jupiter’s are gas giants that orbit very close

to their stars and thus have a very high surface temperature. Hot Jupiter’s were,

until the advent of space borne telescopes, the most common form of extrasolar

planet known, perhaps due to the relative ease of detecting them from ground-

based instruments.

Gas giants are commonly said to lack solid surfaces, but it is more accurate

to say that they lack surfaces altogether since the gases that constitute them simply

become thinner and thinner with increasing distance from the planets' centers,

eventually becoming indistinguishable from the interplanetary medium. Therefore

landing on a gas giant may or may not be possible, depending on the size and

composition of its core.

Maelyn Leis

Though Jupiter has over sixty moons,

its four largest were discovered by Galileo Galilei in 1610 through his telescope. The names of the four moons come from Greek mythology, and are actually the names of Zeus’s four lovers,

Io, Europa, Ganymede, and

Callisto.

The radius of each is greater than even the dwarf planet Ceres in the asteroid belt.

Io is closest to

Jupiter and the fourth largest moon in the solar system. Io is covered in volcanoes and mountains, and is the most

geologically active object in the Solar System. Io has a thin atmosphere and, possibly, a magnetic field.

Europa is

second closest to Jupiter and is smaller than Earth’s moon. There could be life on Europa, since Europa has a layer of

water and ice, and if oceans do in fact exist

on Europa, life similar to that in Earth’s undersea vents could exist. Europa has a thin oxygen atmosphere, an iron core, and markings on the outside that could be the cause of gravity, or could be the cause of geyser eruptions.

Ganymede is the largest satellite in

the solar system--larger than Mercury--and orbits third from Jupiter. It is a frozen moon with a magnetic atmosphere, and, like Europa, its atmosphere is thin and primarily oxygen. The surface is grooved and cratered, but covered in a layer of ice.

Callisto is

the fourth and last moon from Jupiter and is the second largest, as well as the third largest moon in the solar system. Callisto is made up of

rock and ice, and could contain an underground ocean, which could harbor life, though it’s less likely than Europa to harbor life. Its surface is intensely cratered.

Uranus

The seventh planet in our solar system and the second

smallest of the gas giants is the title held by Uranus.

Uranus has 27 moons, all but six were discovered by the

Voyager II flyby mission. The six largest moons are named

after characters in William Shakespeare's plays: Titania,

Oberon, Ubmriel Ariel and Miranda.

Uranus has many different unique qualities from its differ-

ent name pronunciations to its extreme axial tilt.

Uranus orbits

on its side.

Pronunciations:

You’re-anus; Oo-ran-ose, Yourinus

Even though it is bigger, Uranus’ surface gravity is 8.9m/s squared compared to

Earth’s 9.78 m/s squared. Uranus’ mass is 86.81 septillion kg whereas Earth’s is

only 5.972 septillion kg. That’s 21 zeroes!

It takes Uranus eighty four Earth years to orbit the sun and the days on the

planet’s surface last about that long as well. Uranus rotates in 17 hours and 14

minutes with an average speed of 6.8 km/s.

Even though the planet rotates that quickly a Uranian day lasts about as long as

its year. As the planet moves about its orbit, its northern hemisphere is pointed

toward the sun. Then about a quarter year later the equator is pointed at the

sun. At the halfway mark the southern hemisphere is facing the sun then at three

-quarters of a year the equator is facing the sun again but in the opposite direc-

tion, then the cycle repeats.

Uranus’ atmosphere is about 4000km thick and is the coldest atmosphere of the

gas giants with an average temperature of 49 kelvin. It is mainly composed of hy-

drogen and helium at the surface, but the further down you go there is an abun-

dance of methane and ammonia.

There are 11 rings around Uranus, two of which were discovered by the only mis-

sion to the planet, Voyager II, which is no longer orbiting Uranus. Nine rings were

officially discovered in 1978, and two more when Voyager two flew by.

Uranus as seen by Voyager II

By: Braeden Cook

Weather On Jovian Planets

All 4 jovian planets have distinct

atmospheres with cloud layers that

govern the different types of gases that

can condense.

Jupiter's weather is by far the strongest

and most active of the jovian planets,

but weather is found on all four.

Saturn has stripes of alternating color

and wind direction, though in more

color. Even though Saturn has an axis

tilt similar to that of Earth, we don't see

the dramatic seasons we might expect.

Some weather changes have been

seen, but Saturn's internal heat keeps

temperatures about the same.

Uranus is tipped on its side so scientists would expect it to

go through extreme changes during its 84-year orbit around

the Sun. When Voyager 2 flew past in 1986, Uranus's

northern hemisphere was facing directly toward the Sun,

and its southern hemisphere was surrounded by darkness.

Photographs revealed no clouds. More recent observations

show storms in Uranus's atmosphere. The storms may be

there because of the changing seasons as the southern

hemisphere sees sunlight for the first time in decades.

Neptune's atmosphere is banded, and has a high-pressure

storm, called the Great Dark Spot, that is like Jupiter's Great

Red Spot. The Great Dark Spot disappeared in 1994, but was

replaced with a similar storm soon after. Like Saturn,

Neptune has an axis tilt similar to Earth's but it has relatively

little seasonal change because of its internal heat. The heat

created in Neptune's interior is released uniformly and

keeps the temperature about the same year-round and

planet-wide.

By: Lila

Kennedy

10-30-14

7th Period