Name _________________________

Date _________________

Please read the article in the November 2004 Discover magazine, Beyond Pluto and answer the questions

below.

1. What did Kenneth Edgeworth and Gerrd Kuiper predict about the solar system?

2. What lies beyond the Kuiper Belt, what can be found there?

3. What new planet has been discovered in the past few years, how is it different than other planets?

4. Why is there an issue with naming Pluto the ninth planet among astronomers?

5. What makes up the inner solar system?

6. What makes up the outer solar system?

7. What is the youngest structure in the solar system?

A Moon for the "10th Planet"

An article by David Tytell http://skyandtelescope.com/news/article_1603_1.asp?from=astrowire.com

1. Where is this “tenth planet” located? ______________________

2. What is this object called by? ____________________________

3. What was recently discovered about this body that will help substantiate it as a planet? _______________________________

4. How is the Hubble telescope going to help clarify the identity of the planet and its possible moon? ____________________________________________

5. What is the diameter of the satellite? ______________

6. How much bigger is the “planet” than the satellite? _______________

7. Who determines if 2003 UB313 is officially a planet? ___________________________

8. The infrared Spitzer Space Telescope confirmed that 2003 UB313 is larger than the previous Kuiper Belt Object record holder. What planet held that record? _________

9. What does a telescope taste like?

10. How far from the Sun are these objects? ________________________________

11. What are the names of these two objects? _________________________________

Exoplanets

NAME ________________________________________ DATE __________________ PERIOD _____

To answer the questions below go to: http://www.msnbc.msn.com/id/11022898

1. What is an exoplanet? _______________________________________________________________

2. List and describe in your own words TWO of the four methods that astronomers use to find

exoplanets.

Method _____________________ Description _____________________________________________

___________________________________________________________________________________

Method _____________________ Description _____________________________________________

___________________________________________________________________________________

3. Look through some of the exoplanets on the “extrasolar planet finder.” What is the method that was

used to locate the majority of the exoplanets? _______________________________________________

To answer the questions below go to: http://exoplanets.org/planets.shtml

IMPORTANT NOTE: All planetary masses are listed in terms of Jupiter mass (Mjup = 2.5 means a mass

two and one half times greater than the mass of the planet Jupiter) and distances are listed in

astronomical units (AU). The average distance between the Earth and the Sun is 1 AU.

1. ______________________ How many exoplanets have been discovered so far?

2. ______________________ ______________________ Of all the exoplanets listed, give the name

of the planet that orbits the farthest from its central star AND how far away is the planet from it’s star?

3. How does this most distant exoplanet listed compare in size to Jupiter and it’s distance from it’s

central star? (Jupiter is 5 AU from the Sun) ________________________________________________

___________________________________________________________________________________

4. Of the exoplanets listed, list 3 (name & mass ) that are most like that mass of the Earth (0.003 Mjup).

__________________________ __________________________ ________________________

5. Do any of the planets shown orbit closer than Mercury (at 0.3 AU)? ___________________________

6. Of all the planetary systems shown, which is most like our own solar system? (hint: you only have

Jupiter’s information to compare to) EXPLAIN your choice.

___________________________________________________________________________________

___________________________________________________________________________________

___________________________________________________________________________________

Name ______________________________

Hyperspace Survival

1. What are the possible threats from outer space that could end life on Earth?

2. What caused the craters that exist on the moon? Does Earth experience this same

phenomenon?

3. What could happen if an asteroid hits the ocean?

4. How are planet Earth and the rest of the solar system moving around the galaxy, what

pattern is seen in Earth’s history?

5. Where is the danger the greatest and why?

6. What is another name for a comet?

7. What happened to Jupiter in 1994? What could happen to Earth if Jupiter did not exist?

Why?

8. Describe the two possibilities for protecting the human race from the threat of an asteroid

impact?

9. How is the mass of a giant star different compared to the mass of a black hole?

10.How are black holes formed?

11. Approximately how many black holes are there in the Milky Way?

12. How do astronomers find Black holes? Are they really black?

13. How do we track a “non-feeding” black hole, how long did it take to find one?

14. How fast are the stars going at the center of the galaxy, why?

15. What are some possible scenarios if a black hole wandered too close to our Solar

System?

1

Astronomy Student Notes Name __________________

Date _________

The Solar System

Vocabulary: Number and define each term below in a complete sentence on a separate sheet of

paper. (Please illustrate the terms that have a *) Solar System Comparative Planetology Density* Jovian Planets*

Terrestrial Planets* Asteroid Belt* Asteroids* Protosun

M-type asteroids C-types asteroids S-type asteroids Mass

Volcanism* Galileo probe binary asteroids NEAR-Shoemaker craft

Apollo asteroids* Trojan asteroids* Interstellar Dust Condensation Theory

Kirkwood Gaps Comets* Tail Nucleus*

Coma* Hydrogen Envelope* Ions Tails* Dust Tails*

Short-period comets Kuiper Belt* Oort Cloud* Meteor

Meteorite* Meteoroid Meteoroid Swarm Micrometeoroids

Meteor Shower Fireballs Interplanetary Matter Accretion*

Solar Nebula* Evolutionary Theory Catastrophic Theories

Protoplanet

The Solar System

An Inventory of the Solar System

A.Why is comparative planetology important?

-To understand better the conditions under which planets form and evolve

-Goal is to develop a comprehensive theory of the ___________________________ of our

planetary system that explains all, or at least most, of its observed properties

B.How many planets could the ancient Greeks see, what else did they observer?

-The ________, the stars, and five planets—Mercury, Venus, Mars, ______________________

-Comets and __________________

C.What is Ceres, where is it located

-The largest _______________ and the first to be sighted, was discovered in 1801.

D.List all of the contents in the solar system, according to this section:

-One star (the Sun), _______________ planets, ____ moons (at last count) orbiting those planets

-_____ asteroids larger than 300 km in diameter, tens of thousands of smaller (but well-studied)

asteroids

-A myriad of comets a few kilometers in diameter, and countless meteoroids less than 100 m

across. The list will undoubtedly grow as we continue to explore our cosmic neighborhood.

Planetary Properties

A.How is a mass of an object measured in the solar system?

-The masses of planets with ___________ may be calculated by application of ____________

laws of motion and gravity

-Just by observing the moons’ orbits around the planets, the ______ of those orbits, like the

sizes of the planets themselves, are determined by ________________.

B.What is one way we determine a planet’s rotational period?

-Determined simply by watching surface features appear and disappear again as the planet

rotates.

2

-Why can this method be difficult for some planets?

-Surfaces are hard to see or may even be nonexistent. Mercury’s surface features are hard

to distinguish, the surface of Venus is completely obscured by ____________, and

Jupiter, Saturn, Uranus, and Neptune have no ________________________ at all

C.What is the average density of (use proper units):

-Earth- ____________________ of Earth matter in every cubic meter of Earth volume

-Water- _________________

-__________________- 2000–3000 kg/m3,

-____________- 8000 kg/m3

-Earth’s ____________________- a few kilograms per cubic meter

The Overall Layout of the Solar System

A.What is the order of planets outward, how will you remember?

-_______________________________________________________________…

-Mnemonic

B.How are all of the planets in the solar system the same?

- Their paths are all ____________________

- All the planets orbit the Sun in the same sense—____________________ as seen from above

Earth’s North Pole—and in nearly the same plane as Earth (that is, the _______________ plane)

C.List some properties that make the planets different:

-The planetary orbits are not evenly ______________

-???

D.The Titius-Bode ―Law‖

-How does it work?

-The spacing of the orbits increases more or less geometrically as we move out from the

Sun: At any point in the list, the distance to the next planet out is about

________________ to the next planet in.

-What’s wrong with this rule?

- the rule fails for _____________, which lies only 30 A.U. from the Sun. However, if we

ignore Neptune, Pluto is in just about the right place!

Terrestrial and Jovian Planets

A.How are terrestrial planets similar/different?

- All lie within about ________ of the Sun, all are small and of relatively low mass, all have

generally ____________________________ and solid surfaces

-Surface conditions on the four planets are quite distinct from one another, ranging from barren,

heavily cratered terrain on Mercury to widespread volcanic activity on _______________.

- Earth and Mars spin at roughly the same rate—one rotation every 24 (Earth) hours—but

Mercury and Venus both take ___________ to rotate just once, and Venus rotates in the

opposite sense from the others.

- Earth and Mars have moons, but Mercury and Venus do not

B.What makes Terrestrial planets different from Jovian planets (hint: copy table 6.2)

Terrestrial Planet Jovian Planets

-___________ to the Sun -________ from the Sun

-__________ spaced orbits -__________spaced orbits

-small masses -_________masses

-small radii -large _____________

3

-________________ -_______________

-solid surface -__________________

-_______________ -low density

-slow rotation -__________________

-_________________ -strong magnetic field

-few moons -________________

-________________ -many rings

C.What percentage of the solar system mass does the Sun make up? ___________________

Interplanetary Debris

A.What is interplanetary matter?

- cosmic ―debris‖ ranging in size from the relatively _________________, through the smaller

comets and even smaller meteoroids, down to the smallest _______________________ that

litter our cosmic environment.

B.What is the difference between an:

-___________________- generally rocky in composition, Their total mass is much less than that

of Earth’s Moon, so these objects play no important role in the present-day workings of the

planets or their moons.

-___________________- generally icy rather than rocky in composition (although they do

contain some rocky material) and typically have diameters in the 1–10 km range.

C. How do we know what material makes up a meteoroid?

- they often conveniently deliver themselves right to our doorstep, in the form of ____________

allowing us to study them in detail without having to fetch them from space.)

D. How do we know what material makes up a comet?

- Astronomers can determine a comet’s makeup by ____________________________ of the

radiation it gives off as it is destroyed

E. What can we learn from solar system debris?

-Many of these bodies are made of material that has evolved hardly at all since the early days of

the solar system, possible origin of solar system and planets, ______________________?

Solar System Debris

Asteroids

A.Orbital Properties

-Describe an asteroid’s orbit, where are they located in the solar system?

- majority of these bodies are found in a region of the solar system known as the ______

_________________, located between 2.1 and 3.3 A.U. from the Sun—roughly midway

between the orbits of ________ (1.5 A.U.) and _____________ (5.2 A.U.).

-How much of the mass of the solar system is made up of asteroids?

-___________ the mass of the Moon, so they do not contribute significantly to the total

mass of the solar system.

-Where do asteroids come from?

-either the fragments of a planet ______________________ or primal rocks that never

managed to accumulate into a genuine planet

B.Physical Properties

-How are asteroids classified?

- by their spectroscopic properties

4

- _______________(or carbonaceous) asteroids- darkest, or least reflective, asteroids 75

percent are C-type

- ________________ asteroids- more reflective contain silicate, or rocky, material 15

percent of all asteroids are S-type

__________________ asteroids- containing large fractions of nickel and iron ~10 percent

-What are the 3 largest asteroids?

1. __________, 940 km (now dwarf planet)

2. ____________, 580 km

3. ____________, 540 km

-What was the purpose of the NEAR-Shoemaker?

-For one year, the spacecraft sent back high-resolution images of __________, and made

detailed measurements of its size, shape, gravitational and magnetic fields, composition,

and structure. The craft’s various sensors revealed Eros to be a ___________________

body of mass 7 1015

kg and roughly uniform density around 2700 kg/m3

-February 12, 2001, NEAR-Shoemaker landed on Eros, sending back a series of close-up

images as it descended to the surface

C.Earth Crossing Asteroids

-Describe why an asteroid with an eccentricity _________ interests astronomers?

- their paths may intersect Earth’s orbit, leading to the possibility of a collision with our

planet

-What are these asteroids called?

- termed ________________ (after the first known Earth-crossing asteroid, Apollo

-How often is the Earth struck by asteroids?

- On average during any given million-year period our planet is struck by about

__________________________

-What kind of effects would an asteroid collision have?

- a visit of even a kilometer-sized asteroid to Earth could be catastrophic by human

standards. Such an object packs enough energy to devastate an area some ________ in

diameter. The explosive power would be equivalent to about a _____________________

___________________—a hundred times more than all the nuclear weapons currently in

existence

-What has been done to prevent asteroids from colliding with Earth?

- Some astronomers take the prospect of an asteroid impact sufficiently seriously that

they maintain an "____________________"—an effort to catalog and monitor all Earth-

crossing asteroids in order to maximize our warning time of any impending collision.

-What evidence indicates that an asteroid or comet led to the demise of the dinosaurs?

- main geological evidence supporting this theory is a layer of clay enriched with the

element ___________________. This layer is found in _________________________

rocky sediments all around our planet.

-The abundance of iridium in this one layer of clay is about 10 times greater than in other

terrestrial rocks, but it matches closely the abundance of iridium found in ____________

-The site of the catastrophic impact has also been tentatively identified near

___________________, in the Yucatan Peninsula in Mexico, where evidence of a

heavily eroded, but not completely obliterated, crater of just the right size and age has

been found.

D.Orbital Resonances

-What are _____________ asteroids?

5

-asteroids that orbit at the distance of Jupiter, either in front or behind the planet

-What are ______________________ and what causes them?

- Gaps in the spacings of semi-major axes of orbits of asteroids in the asteroid belt,

produced by dynamical resonances with nearby planets, especially Jupiter.

Comets

-When do comets become brighter, how do they change shape?

- comet brightens and develops an extended tail as it __________________. (The name

"comet" derives from the Greek word kome, meaning "hair.")

-As the comet departs from the Sun’s vicinity, ________________________ diminish

until it once again becomes a faint point of light receding into the distance.

A.Comet Appearance and Structure

-Diagram a comet, include the nucleus, coma, hydrogen envelope and tail:

-What are the two types of comet tails?

- ________ tails are approximately straight, often made up of glowing, linear streamers

-_________ tails are usually broad, diffuse, and gently curved, rich in microscopic dust

particles that reflect sunlight, making the tail visible from afar

B.Comet Orbits

-What is the ______________________?

- A region in the plane of the solar system outside the orbit of Neptune where most short-

period comets are thought to originate.

- move in roughly circular orbits between about 30 and 100 A.U. from the Sun, never

venturing inside the orbits of the _________________________

-How can we see objects from the Kuiper Belt?

- Occasionally, however, a close encounter between two comets, or (more likely) the

cumulative gravitational influence of one of the outer planets, "kicks" a Kuiper belt

comet into an eccentric orbit that brings it into the inner solar system, and into our view

-What is the ______________________?

- Spherical halo of material surrounding the solar system, out to a distance of about

_________________________ A.U., where most comets originate.

C.A Visit to Halley’s Comet

-Why is Halley’s Comet so popular?

- In 1705 the British astronomer _______________________ calculated its path and

found that the comet orbited the Sun with a period of _____________________.

-Halley’s successful determination of the comet’s trajectory and his prediction of its

return was an early triumph of _____________________________________

-How did spacecraft study it, what did they learn from these missions?

- Halley’s comet rounded the Sun in ____________, Soviet craft, Vega 2, traveled

through the comet’s coma and came within 8000 km of the nucleus

- the European Giotto spacecraft was navigated to within 600 km of the nucleus, at _____

km/s—the speed of the craft relative to the comet—a colliding dust particle becomes a

devastating bullet. Debris did in fact damage Giotto’s camera, but not before it sent home

a wealth of data

6

-What happens to a comet’s mass over time?

-A comet’s mass decreases with time because some material is lost each time the comet

rounds the Sun as material ____________________ from its surface

-Comets that travel within an astronomical unit of the Sun, the evaporation rate can reach

as high as 1030

molecules per second—about ___________________________________

________________ the comet spends near the Sun

-Why will Halley’s Comet be destroyed in about 40,000 years?

-Loss of material will destroy Halley’s comet in about ______________, or 40,000 years

D.Physical Properties of Comets

-What is the physical makeup of a comet?

-Comets are made of dust particles trapped within a mixture of ____________________,

carbon dioxide, and ordinary water ice, because of this composition, comets are often

described as "______________________."

E.A Cometary Impact

-What happened with the Comet-Shoemaker-Levy 9?

-___________- the collision of a comet (called Shoemaker-Levy 9, after its discoverers)

with the planet Jupiter

- energy released in each explosion was comparable to a __________________ terrestrial

nuclear detonations, rivaling in violence the prehistoric impact suspected of causing the

extinction of the dinosaurs on Earth 65 million years ago

Meteoroids

-What is the difference between a:

1._______________ -sudden streak of light in the night sky caused by friction between

air molecules in Earth’s atmosphere and an incoming piece of interplanetary matter

2._______________ -Before encountering the atmosphere, the piece of debris causing a

meteor

3.________________ Any piece of interplanetary debris that survives its fiery passage

through our atmosphere and finds its way to the ground

-What makes an asteroid different from meteoroid?

-Meteoroids are conventionally taken to be less than _________________________

-What is needed for a meteor shower?

- Earth’s orbit happens to intersect the orbit of a young cluster of meteoroids, from

broken up _______________________

-What are meteor showers named after?

- Meteor showers are usually named for their ___________________, the constellation

from whose direction they appear to come

-What are fireballs?

- A few large __________________________________ at such high speed (about 75

km/s) that they either fragment or disperse entirely at high altitudes.

-How do meteors make it to the surface of the Earth?

- The more massive meteoroids (at least a ton in mass and a meter across) do make it to

the surface, producing a crater such as the kilometer-wide _______________________

-How come there are not more craters on Earth?

- Most of the craters are so heavily eroded by weather and distorted by crustal activity

that they can be identified only in ____________________________

-What happened in central Siberia in 1908?

7

-June 30, 1908 lack of fragments implies that this Siberian intruder exploded several

kilometers ____________________, leaving a blasted depression at ground level but no

well-formed crater.

-Recent calculations suggest that the object in question was a rocky meteoroid about

______ across. The explosion, estimated to have been equal in energy to a 10-megaton

nuclear detonation, was heard hundreds of kilometers away and produced measurable

increases in atmospheric dust levels all across the ______________________________.

-How are meteors similar/different?

- Most meteorites are rocky in composition, although a few percent are composed mainly

of ___________________________

-Some meteorites show clear evidence of strong heating at some time in their past, most

likely indicating that they originated on a larger body that either experienced some

geological activity or was partially melted during the collision, others show no such

evidence and probably date from the ___________________________________.

- almost all meteorites are old. Direct ______________________shows most of them to

be between 4.4 and 4.6 billion years old—roughly the age of the oldest lunar rocks.

Meteorites, along with some lunar rocks, comets, and perhaps the planet Pluto, provide

essential clues to the original state of matter in the solar neighborhood. Modeling the Origin of the Solar System

A.What are the 9 properties/rules of the solar system?

1. Each planet is in an isolated _________________

2. The orbit of the planets is nearly _______________

3.All orbits are in about the same __________________

4.Sun’s ________________ direction=planet’s rev. direction

5.Most planets mimic rotation of the ____________

6. Most moons revolve in same way ____________________

7. Planets are highly ______________________

8.Asteroids are very old, don’t fit inner or outer _______________

9.Comets do not orbit along ecliptic, have very large ______________

The Condensation Theory

A.What is the Nebular Theory?

-Large cloud of interstellar gas collapsed, becomes ____________________ to form the Sun at

the center- swirling mass is called the ___________________

B.What caused the Solar System to get its flat shape?

-Gravity and rotation speed (like a pizza!), creates rings that eventually become

_________________, just like Saturn’s rings eventually form moons

C.How is the condensation theory different from the nebular theory?

-Nebular Theory + _________________, answers old theory’s problems= Condensation Theory

D.How does accretion create planetestimals?

-Accretion is the gradual growth by collisions and sticking and eventually objects grow to

thousands of kilometers across= ___________________

E.How long did heavy meteorites bombardment take place in the Solar System?

-The _________________ of Solar System formation

8

The Differentiation of the Solar System

A.What are the 5 most common elements in the Solar System?

-Hydrogen, ____________, Carbon, Nitrogen, and ______________

B.Why did Jovian planets grow so large compared to terrestrial planets?

-More material could ____________ due to being far out from the protosun heat, so accretions

started earlier

C.Where did Earth get its water from?

-Two possible ways: Comet bombardment and continuous ______________________

D.What is the T-tauri phase?

-Young star phase when _________________ are very intense and blow out any remaining gas-

only objects remaining are protoplanets and planetestimals

The Role of Catastrophes

A.How have possible collisions affected the following planets?

-___________-Collision may have caused two cores to merge creating its large iron-nickel core

-___________-Low rotation rate of 243 days (225 for revolution) result of a collision, also

retrograde

-__________- Moon caused by Mars sized object collision

-____________- Late collisions caused loss of atmosphere?

-_____________-Tilted rotation its side also retrograde, collision?

Its moon Miranda- very bizarre surface terrane, see chapter on Uranus

-_______________-Moon- Triton has retrograde motion

Planets Beyond the Solar System

A.What important discovery occurred in 1995?

-The first confirmed _________________ planet was discovered due to improvement in

telescopes and computing power

B.What are two possible ways of detecting extrasolar planets?

1.Looking for the __________ of a star due to gravity from a large planet, the greater the mass

of the planet the larger the wobble

2._________________- if the diameter of a planet is large enough we can see a planet transit a

star, just like Mercury does from the Sun

C.Why has it been difficult to find Earth-sized planets?

-lightweight planets simply don’t produce large enough velocity fluctuations to be detectable

-Can only find planets with masses the size of ___________________ but orbit very closely to

the star (called Hot Jupiters)

9

Distance

from the

Sun

Diameter

Length

of

Rotation

(Day)

Length of

Revolution

(Year)

Composition

of Planet

Composition

of

Atmosphere

Number

of

known

satellites

Sun

Mercury

Venus

Earth

Mars

Jupiter

Saturn

Uranus

Neptune

Pluto

Ceres